Fossil

  u8 scanstatsOn;        /* True to display scan stats before each finalize */
  u8 openMode;           /* SHELL_OPEN_NORMAL, _APPENDVFS, or _ZIPFILE */
  u8 doXdgOpen;          /* Invoke start/open/xdg-open in output_reset() */
  u8 nEqpLevel;          /* Depth of the EQP output graph */
  u8 eTraceType;         /* SHELL_TRACE_* value for type of trace */
  u8 bSafeMode;          /* True to prohibit unsafe operations */
  u8 bSafeModePersist;   /* The long-term value of bSafeMode */
  u8 bQuote;             /* Quote results for .mode box and table */
  int iWrap;             /* Wrap lines this long or longer in some output modes */
  unsigned statsOn;      /* True to display memory stats before each finalize */
  unsigned mEqpLines;    /* Mask of veritical lines in the EQP output graph */
  int inputNesting;      /* Track nesting level of .read and other redirects */
  int outCount;          /* Revert to stdout when reaching zero */
  int cnt;               /* Number of records displayed so far */
  int lineno;            /* Line number of last line read from in */
  int openFlags;         /* Additional flags to open.  (SQLITE_OPEN_NOFOLLOW) */

      print_box_line(p->out, p->actualWidth[i]+2);
    }
    utf8_printf(p->out, "%s", zSep3);
  }
  fputs("\n", p->out);
}

/*
** z[] is a line of text that is to be displayed the .mode box or table or
** similar tabular formats.  z[] might contain control characters such
** as \n, \t, \f, or \r.
**
** Compute characters to display on the first line of z[].  Stop at the
** first \r, \n, or \f.  Expand \t into spaces.  Return a copy (obtained
** from malloc()) of that first line.  Write anything to display
** on the next line into *pzTail.  If this is the last line, write a NULL
** into *pzTail.
*/
static char *translateForDisplayAndDup(
  const unsigned char *z,
  const unsigned char **pzTail,
  int mxWidth
){
  int i, j, n;
  unsigned char *zOut;
  if( z==0 ){
    *pzTail = 0;
    return 0;
  }
  if( mxWidth<0 ) mxWidth = -mxWidth;
  if( mxWidth==0 ) mxWidth = 1000000;
  i = j= n = 0;
  while( n<mxWidth ){
    if( z[i]>=' ' ){
      n++;
      do{ i++; j++; }while( (z[i]&0xc0)==0x80 );
      continue;
    }
    if( z[i]=='\t' ){
      do{
        n++;
        j++;
      }while( (n&7)!=0 && n<mxWidth );
      n += 8;
      n &= ~7;
      i++;
      continue;
    }
    break;
  }
  if( n>=mxWidth && z[i]>=' ' ){
   *pzTail = &z[i];
  }else if( z[i]=='\r' && z[i+1]=='\n' ){
    *pzTail = z[i+2] ? &z[i+2] : 0;
  }else if( z[i]==0 || z[i+1]==0 ){
    *pzTail = 0;
  }else{
    *pzTail = &z[i+1];
  }
  zOut = malloc( j+1 );
  shell_check_oom(zOut);
  i = j = n = 0;
  while( n<mxWidth ){
    if( z[i]>=' ' ){
      n++;
      do{ zOut[j++] = z[i++]; }while( (z[i]&0xc0)==0x80 );
      continue;
    }
    if( z[i]=='\t' ){
      do{
        n++;
        zOut[j++] = ' ';
      }while( (n&7)!=0 && n<mxWidth );
      i++;
      continue;
    }
    break;
  }
  zOut[j] = 0;
  return (char*)zOut;  
}

/* Extract the value of the i-th current column for pStmt as an SQL literal
** value.  Memory is obtained from sqlite3_malloc64() and must be freed by
** the caller.
*/
static char *quoted_column(sqlite3_stmt *pStmt, int i){
  switch( sqlite3_column_type(pStmt, i) ){
    case SQLITE_NULL: {
      return sqlite3_mprintf("NULL");
    }
    case SQLITE_INTEGER:
    case SQLITE_FLOAT: {
      return sqlite3_mprintf("%s",sqlite3_column_text(pStmt,i));
    }
    case SQLITE_TEXT: {
      return sqlite3_mprintf("%Q",sqlite3_column_text(pStmt,i));
    }
    case SQLITE_BLOB: {
      int j;
      sqlite3_str *pStr = sqlite3_str_new(0);
      const unsigned char *a = sqlite3_column_blob(pStmt,i);
      int n = sqlite3_column_bytes(pStmt,i);
      sqlite3_str_append(pStr, "x'", 2);
      for(j=0; j<n; j++){
        sqlite3_str_appendf(pStr, "%02x", a[j]);
      }
      sqlite3_str_append(pStr, "'", 1);
      return sqlite3_str_finish(pStr);
    }
  }
  return 0; /* Not reached */
}

/*
** Run a prepared statement and output the result in one of the
** table-oriented formats: MODE_Column, MODE_Markdown, MODE_Table,
** or MODE_Box.
**
** This is different from ordinary exec_prepared_stmt() in that
** it has to run the entire query and gather the results into memory
** first, in order to determine column widths, before providing
** any output.
*/
static void exec_prepared_stmt_columnar(
  ShellState *p,                        /* Pointer to ShellState */
  sqlite3_stmt *pStmt                   /* Statment to run */
){
  sqlite3_int64 nRow = 0;
  int nColumn = 0;
  char **azData = 0;
  sqlite3_int64 nAlloc = 0;
  char *abRowDiv = 0;
  const unsigned char *uz;
  const char *z;
  char **azQuoted = 0;
  int rc;
  sqlite3_int64 i, nData;
  int j, nTotal, w, n;
  const char *colSep = 0;
  const char *rowSep = 0;
  const unsigned char **azNextLine = 0;
  int bNextLine = 0;
  int bMultiLineRowExists = 0;

  rc = sqlite3_step(pStmt);
  if( rc!=SQLITE_ROW ) return;
  nColumn = sqlite3_column_count(pStmt);
  nAlloc = nColumn*4;
  if( nAlloc<=0 ) nAlloc = 1;
  azData = sqlite3_malloc64( nAlloc*sizeof(char*) );
  shell_check_oom(azData);
  azNextLine = sqlite3_malloc64( nColumn*sizeof(char*) );
  shell_check_oom(azNextLine);
  memset(azNextLine, 0, nColumn*sizeof(char*) );


  if( p->bQuote ){

    azQuoted = sqlite3_malloc64( nColumn*sizeof(char*) );
    shell_check_oom(azQuoted);


    memset(azQuoted, 0, nColumn*sizeof(char*) );


  }
  abRowDiv = sqlite3_malloc64( nAlloc/nColumn );
  shell_check_oom(abRowDiv);
  if( nColumn>p->nWidth ){
    p->colWidth = realloc(p->colWidth, (nColumn+1)*2*sizeof(int));
    shell_check_oom(p->colWidth);
    for(i=p->nWidth; i<nColumn; i++) p->colWidth[i] = 0;
    p->nWidth = nColumn;
    p->actualWidth = &p->colWidth[nColumn];
  }
  memset(p->actualWidth, 0, nColumn*sizeof(int));
  for(i=0; i<nColumn; i++){
    w = p->colWidth[i];
    if( w<0 ) w = -w;
    p->actualWidth[i] = w;
  }
  for(i=0; i<nColumn; i++){
    azData[i] = strdup(sqlite3_column_name(pStmt,i));
  }
  do{
    int useNextLine = bNextLine;
    bNextLine = 0;
    if( (nRow+2)*nColumn >= nAlloc ){
      nAlloc *= 2;
      azData = sqlite3_realloc64(azData, nAlloc*sizeof(char*));
      shell_check_oom(azData);
      abRowDiv = sqlite3_realloc64(abRowDiv, nAlloc/nColumn);
      shell_check_oom(abRowDiv);
    }
    abRowDiv[nRow] = 1;
    nRow++;
    for(i=0; i<nColumn; i++){
      int w = p->colWidth[i];
      if( w==0 ) w = p->iWrap;
      if( useNextLine ){
        uz = azNextLine[i];
      }else if( p->bQuote ){
        sqlite3_free(azQuoted[i]);
        azQuoted[i] = quoted_column(pStmt,i);
        uz = (const unsigned char*)azQuoted[i];
      }else{
        uz = (const unsigned char*)sqlite3_column_text(pStmt,i);
      }
      azData[nRow*nColumn + i] = translateForDisplayAndDup(uz, &azNextLine[i], w);
      if( azNextLine[i] ){
        bNextLine = 1;
        abRowDiv[nRow-1] = 0;
        bMultiLineRowExists = 1;
      }
    }
  }while( bNextLine || sqlite3_step(pStmt)==SQLITE_ROW );
  nTotal = nColumn*(nRow+1);
  for(i=0; i<nTotal; i++){
    z = azData[i];
    if( z==0 ) z = p->nullValue;
    n = strlenChar(z);
    j = i%nColumn;
    if( n>p->actualWidth[j] ) p->actualWidth[j] = n;

    z = azData[i];
    if( z==0 ) z = p->nullValue;
    w = p->actualWidth[j];
    if( p->colWidth[j]<0 ) w = -w;
    utf8_width_print(p->out, w, z);
    if( j==nColumn-1 ){
      utf8_printf(p->out, "%s", rowSep);
      if( bMultiLineRowExists && abRowDiv[i/nColumn-1] && i+1<nTotal ){
        if( p->cMode==MODE_Table ){
          print_row_separator(p, nColumn, "+");
        }else if( p->cMode==MODE_Box ){
          print_box_row_separator(p, nColumn, BOX_123, BOX_1234, BOX_134);
        }
      }
      j = -1;
      if( seenInterrupt ) goto columnar_end;
    }else{
      utf8_printf(p->out, "%s", colSep);
    }
  }
  if( p->cMode==MODE_Table ){
    print_row_separator(p, nColumn, "+");
  }else if( p->cMode==MODE_Box ){
    print_box_row_separator(p, nColumn, BOX_12, BOX_124, BOX_14);
  }
columnar_end:
  if( seenInterrupt ){
    utf8_printf(p->out, "Interrupt\n");
  }
  nData = (nRow+1)*nColumn;
  for(i=0; i<nData; i++) free(azData[i]);
  sqlite3_free(azData);
  sqlite3_free(azNextLine);
  sqlite3_free(abRowDiv);
  if( azQuoted ){
    for(i=0; i<nColumn; i++) sqlite3_free(azQuoted[i]);
    sqlite3_free(azQuoted);
  }
}

/*
** Run a prepared statement
*/
static void exec_prepared_stmt(
  ShellState *pArg,                                /* Pointer to ShellState */

  ".lint OPTIONS            Report potential schema issues.",
  "     Options:",
  "        fkey-indexes     Find missing foreign key indexes",
#ifndef SQLITE_OMIT_LOAD_EXTENSION
  ".load FILE ?ENTRY?       Load an extension library",
#endif
  ".log FILE|off            Turn logging on or off.  FILE can be stderr/stdout",
  ".mode MODE ?TABLE? ?OPTIONS?      Set output mode",
  "   MODE is one of:",
  "     ascii       Columns/rows delimited by 0x1F and 0x1E",
  "     box         Tables using unicode box-drawing characters",
  "     csv         Comma-separated values",
  "     column      Output in columns.  (See .width)",
  "     html        HTML <table> code",
  "     insert      SQL insert statements for TABLE",
  "     json        Results in a JSON array",
  "     line        One value per line",
  "     list        Values delimited by \"|\"",
  "     markdown    Markdown table format",
  "     qbox        Shorthand for \"box --width 60 --quote\"",
  "     quote       Escape answers as for SQL",
  "     table       ASCII-art table",
  "     tabs        Tab-separated values",
  "     tcl         TCL list elements",
  "   OPTIONS: (value for columnar modes only):",
  "     --wrap N    Wrap output lines longer than N character",
  "     --quote     Quote output text as SQL literals",
  "     --noquote   Do not quote output text",
  ".nonce STRING            Disable safe mode for one command if the nonce matches",
  ".nullvalue STRING        Use STRING in place of NULL values",
  ".once ?OPTIONS? ?FILE?   Output for the next SQL command only to FILE",
  "     If FILE begins with '|' then open as a pipe",
  "       --bom  Put a UTF8 byte-order mark at the beginning",
  "       -e     Send output to the system text editor",
  "       -x     Send output as CSV to a spreadsheet (same as \".excel\")",

      const char *zFile = azArg[1];
      output_file_close(p->pLog);
      p->pLog = output_file_open(zFile, 0);
    }
  }else

  if( c=='m' && strncmp(azArg[0], "mode", n)==0 ){
    const char *zMode = 0;
    const char *zTabname = 0;
    int i, n2;
    int bQuoteChng = 0;
    int bWrapChng = 0;
    for(i=1; i<nArg; i++){
      const char *z = azArg[i];
      if( optionMatch(z,"wrap") && i+1<nArg ){
        p->iWrap = integerValue(azArg[++i]);
        bWrapChng = 1;
      }else if( optionMatch(z,"quote") ){
        p->bQuote = 1;
        bQuoteChng = 1;
      }else if( optionMatch(z,"noquote") ){
        p->bQuote = 0;
        bQuoteChng = 1;
      }else if( zMode==0 ){
        zMode = z;
      }else if( zTabname==0 ){
        zTabname = z;
      }else if( z[0]=='-' ){
        utf8_printf(stderr, "unknown option: %s\n", z);
        utf8_printf(stderr, "options:\n"
                            "  --noquote\n"
                            "  --quote\n"
                            "  --wrap N\n");
        rc = 1;
        goto meta_command_exit;
      }else{
        utf8_printf(stderr, "extra argument: \"%s\"\n", z);
        rc = 1;
        goto meta_command_exit;
      }
    }
    if( zMode==0 ){
      if( p->mode==MODE_Column
       || (p->mode>=MODE_Markdown && p->mode<=MODE_Box)
      ){
        raw_printf(p->out, "current output mode: %s --wrap %d --%squote\n",
                   modeDescr[p->mode], p->iWrap, p->bQuote ? "" : "no");
      }else{
        raw_printf(p->out, "current output mode: %s\n", modeDescr[p->mode]);
      }
      bWrapChng = bQuoteChng = 1;
      zMode = modeDescr[p->mode];
    }
    n2 = strlen30(zMode);

    if( strncmp(zMode,"lines",n2)==0 ){
      p->mode = MODE_Line;
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_Row);
    }else if( strncmp(zMode,"columns",n2)==0 ){
      p->mode = MODE_Column;
      if( (p->shellFlgs & SHFLG_HeaderSet)==0 ){
        p->showHeader = 1;
      }
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_Row);
      if( !bWrapChng ) p->iWrap = 0;
      if( !bQuoteChng ) p->bQuote = 0;
    }else if( strncmp(zMode,"list",n2)==0 ){
      p->mode = MODE_List;
      sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Column);
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_Row);
    }else if( strncmp(zMode,"html",n2)==0 ){
      p->mode = MODE_Html;
    }else if( strncmp(zMode,"tcl",n2)==0 ){
      p->mode = MODE_Tcl;
      sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Space);
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_Row);
    }else if( strncmp(zMode,"csv",n2)==0 ){
      p->mode = MODE_Csv;
      sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Comma);
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_CrLf);
    }else if( strncmp(zMode,"tabs",n2)==0 ){
      p->mode = MODE_List;
      sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Tab);
    }else if( strncmp(zMode,"insert",n2)==0 ){
      p->mode = MODE_Insert;
      set_table_name(p, zTabname ? zTabname : "table");
    }else if( strncmp(zMode,"quote",n2)==0 ){
      p->mode = MODE_Quote;
      sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Comma);
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_Row);
    }else if( strncmp(zMode,"ascii",n2)==0 ){
      p->mode = MODE_Ascii;
      sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Unit);
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_Record);
    }else if( strncmp(zMode,"markdown",n2)==0 ){
      p->mode = MODE_Markdown;
      if( !bWrapChng ) p->iWrap = 0;
      if( !bQuoteChng ) p->bQuote = 0;
    }else if( strncmp(zMode,"table",n2)==0 ){
      p->mode = MODE_Table;
      if( !bWrapChng ) p->iWrap = 0;
      if( !bQuoteChng ) p->bQuote = 0;
    }else if( strncmp(zMode,"box",n2)==0 ){
      p->mode = MODE_Box;
      if( !bWrapChng ) p->iWrap = 0;
      if( !bQuoteChng ) p->bQuote = 0;
    }else if( strcmp(zMode,"qbox")==0 ){
      p->mode = MODE_Box;
      if( !bWrapChng ) p->iWrap = 60;
      if( !bQuoteChng ) p->bQuote = 1;
    }else if( strncmp(zMode,"count",n2)==0 ){
      p->mode = MODE_Count;
    }else if( strncmp(zMode,"off",n2)==0 ){
      p->mode = MODE_Off;
    }else if( strncmp(zMode,"json",n2)==0 ){
      p->mode = MODE_Json;


    }else{
      raw_printf(stderr, "Error: mode should be one of: "
         "ascii box column csv html insert json line list markdown "
         "qbox quote table tabs tcl\n");
      rc = 1;
    }
    p->cMode = p->mode;
  }else

  if( c=='n' && strcmp(azArg[0], "nonce")==0 ){
    if( nArg!=2 ){

    }
    utf8_printf(p->out, "%12.12s: %s\n","echo",
                                  azBool[ShellHasFlag(p, SHFLG_Echo)]);
    utf8_printf(p->out, "%12.12s: %s\n","eqp", azBool[p->autoEQP&3]);
    utf8_printf(p->out, "%12.12s: %s\n","explain",
         p->mode==MODE_Explain ? "on" : p->autoExplain ? "auto" : "off");
    utf8_printf(p->out,"%12.12s: %s\n","headers", azBool[p->showHeader!=0]);
    if( p->mode==MODE_Column
     || (p->mode>=MODE_Markdown && p->mode<=MODE_Box)
    ){
      utf8_printf(p->out, "%12.12s: %s --wrap %d --%squote\n", "mode",
                  modeDescr[p->mode], p->iWrap, p->bQuote ? "" : "no");
    }else{
      utf8_printf(p->out, "%12.12s: %s\n","mode", modeDescr[p->mode]);
    }
    utf8_printf(p->out, "%12.12s: ", "nullvalue");
      output_c_string(p->out, p->nullValue);
      raw_printf(p->out, "\n");
    utf8_printf(p->out,"%12.12s: %s\n","output",
            strlen30(p->outfile) ? p->outfile : "stdout");
    utf8_printf(p->out,"%12.12s: ", "colseparator");
      output_c_string(p->out, p->colSeparator);

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.38.0"
#define SQLITE_VERSION_NUMBER 3038000
#define SQLITE_SOURCE_ID      "2022-01-31 14:14:29 539cef5214446a7181614793e9cf323e95ba00ba0f888585b14b598dd2ff0808"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

** sqlite3_value objects and they can be used interchangeably.  However,
** for maximum code portability it is recommended that applications
** still make the distinction between protected and unprotected
** sqlite3_value objects even when not strictly required.
**
** ^The sqlite3_value objects that are passed as parameters into the
** implementation of [application-defined SQL functions] are protected.
** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
** are protected.
** ^The sqlite3_value object returned by
** [sqlite3_column_value()] is unprotected.
** Unprotected sqlite3_value objects may only be used as arguments
** to [sqlite3_result_value()], [sqlite3_bind_value()], and
** [sqlite3_value_dup()].
** The [sqlite3_value_blob | sqlite3_value_type()] family of
** interfaces require protected sqlite3_value objects.

#define SQLITE_INDEX_SCAN_UNIQUE      1     /* Scan visits at most 1 row */

/*
** CAPI3REF: Virtual Table Constraint Operator Codes
**
** These macros define the allowed values for the
** [sqlite3_index_info].aConstraint[].op field.  Each value represents
** an operator that is part of a constraint term in the WHERE clause of
** a query that uses a [virtual table].
**
** ^The left-hand operand of the operator is given by the corresponding
** aConstraint[].iColumn field.  ^An iColumn of -1 indicates the left-hand
** operand is the rowid.
** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
** operators have no left-hand operand, and so for those operators the
** corresponding aConstraint[].iColumn is meaningless and should not be
** used.
**
** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
** value 255 are reserved to represent functions that are overloaded
** by the [xFindFunction|xFindFunction method] of the virtual table
** implementation.
**
** The right-hand operands for each constraint might be accessible using
** the [sqlite3_vtab_rhs_value()] interface.  Usually the right-hand
** operand is only available if it appears as a single constant literal
** in the input SQL.  If the right-hand operand is another column or an
** expression (even a constant expression) or a parameter, then the
** sqlite3_vtab_rhs_value() probably will not be able to extract it.
** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
** and hence calls to sqlite3_vtab_rhs_value() for those operators will
** always return SQLITE_NOTFOUND.
**
** The collating sequence to be used for comparison can be found using
** the [sqlite3_vtab_collation()] interface.  For most real-world virtual
** tables, the collating sequence of constraints does not matter (for example
** because the constraints are numeric) and so the sqlite3_vtab_collation()
** interface is no commonly needed.
*/
#define SQLITE_INDEX_CONSTRAINT_EQ          2
#define SQLITE_INDEX_CONSTRAINT_GT          4
#define SQLITE_INDEX_CONSTRAINT_LE          8
#define SQLITE_INDEX_CONSTRAINT_LT         16
#define SQLITE_INDEX_CONSTRAINT_GE         32
#define SQLITE_INDEX_CONSTRAINT_MATCH      64
#define SQLITE_INDEX_CONSTRAINT_LIKE       65
#define SQLITE_INDEX_CONSTRAINT_GLOB       66
#define SQLITE_INDEX_CONSTRAINT_REGEXP     67
#define SQLITE_INDEX_CONSTRAINT_NE         68
#define SQLITE_INDEX_CONSTRAINT_ISNOT      69
#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL  70
#define SQLITE_INDEX_CONSTRAINT_ISNULL     71
#define SQLITE_INDEX_CONSTRAINT_IS         72
#define SQLITE_INDEX_CONSTRAINT_LIMIT      73
#define SQLITE_INDEX_CONSTRAINT_OFFSET     74
#define SQLITE_INDEX_CONSTRAINT_FUNCTION  150

/*
** CAPI3REF: Register A Virtual Table Implementation
** METHOD: sqlite3
**
** ^These routines are used to register a new [virtual table module] name.
** ^Module names must be registered before

*/
SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);

/*
** CAPI3REF: Determine if a virtual table query is DISTINCT
** METHOD: sqlite3_index_info
**
** This API may only be used from within an [xBestIndex|xBestIndex method]
** of a [virtual table] implementation. The result of calling this
** interface from outside of xBestIndex() is undefined and probably harmful.
**
** ^The sqlite3_vtab_distinct() interface returns an integer that is
** either 0, 1, or 2.  The integer returned by sqlite3_vtab_distinct()
** gives the virtual table additional information about how the query
** planner wants the output to be ordered. As long as the virtual table
** can meet the ordering requirements of the query planner, it may set
** the "orderByConsumed" flag.
**
** <ol><li value="0"><p>
** ^If the sqlite3_vtab_distinct() interface returns 0, that means
** that the query planner needs the virtual table to return all rows in the
** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
** [sqlite3_index_info] object.  This is the default expectation.  If the
** virtual table outputs all rows in sorted order, then it is always safe for
** the xBestIndex method to set the "orderByConsumed" flag, regardless of
** the return value from sqlite3_vtab_distinct().
** <li value="1"><p>
** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
** that the query planner does not need the rows to be returned in sorted order
** as long as all rows with the same values in all columns identified by the
** "aOrderBy" field are adjacent.)^  This mode is used when the query planner
** is doing a GROUP BY.
** <li value="2"><p>
** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
** that the query planner does not need the rows returned in any particular
** order, as long as rows with the same values in all "aOrderBy" columns
** are adjacent.)^  ^(Furthermore, only a single row for each particular
** combination of values in the columns identified by the "aOrderBy" field
** needs to be returned.)^  ^It is always ok for two or more rows with the same
** values in all "aOrderBy" columns to be returned, as long as all such rows
** are adjacent.  ^The virtual table may, if it chooses, omit extra rows
** that have the same value for all columns identified by "aOrderBy".
** ^However omitting the extra rows is optional.
** This mode is used for a DISTINCT query.
** </ol>
**

*/
SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);

/*
** CAPI3REF: Constraint values in xBestIndex()
** METHOD: sqlite3_index_info
**
** This API may only be used from within the [xBestIndex|xBestIndex method]
** of a [virtual table] implementation. The result of calling this interface
** from outside of an xBestIndex method are undefined and probably harmful.
**
** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
** the [xBestIndex] method of a [virtual table] implementation, with P being
** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
** J being a 0-based index into P->aConstraint[], then this routine
** attempts to set *V to the value of the right-hand operand of
** that constraint if the right-hand operand is known.  ^If the
** right-hand operand is not known, then *V is set to a NULL pointer.
** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
** and only if *V is set to a value.  ^The sqlite3_vtab_rhs_value(P,J,V)
** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
** constraint is not available.  ^The sqlite3_vtab_rhs_value() interface
** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if
** something goes wrong.
**
** The sqlite3_vtab_rhs_value() interface is usually only successful if
** the right-hand operand of a constraint is a literal value in the original
** SQL statement.  If the right-hand operand is an expression or a reference
** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
** will probably return [SQLITE_NOTFOUND].
**
** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand.  For such
** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
**
** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
** and remains valid for the duration of the xBestIndex method call.
** ^When xBestIndex returns, the sqlite3_value object returned by
** sqlite3_vtab_rhs_value() is automatically deallocated.
**
** The "_rhs_" in the name of this routine is an appreviation for
** "Right-Hand Side".
*/
SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);

/*
** CAPI3REF: Conflict resolution modes
** KEYWORDS: {conflict resolution mode}
**

#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
SQLITE_PRIVATE Expr *sqlite3LimitWhere(Parse*,SrcList*,Expr*,ExprList*,Expr*,char*);
#endif
SQLITE_PRIVATE void sqlite3CodeChangeCount(Vdbe*,int,const char*);
SQLITE_PRIVATE void sqlite3DeleteFrom(Parse*, SrcList*, Expr*, ExprList*, Expr*);
SQLITE_PRIVATE void sqlite3Update(Parse*, SrcList*, ExprList*,Expr*,int,ExprList*,Expr*,
                   Upsert*);
SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(Parse*,SrcList*,Expr*,ExprList*,
                             ExprList*,Select*,u16,int);
SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo*);
SQLITE_PRIVATE LogEst sqlite3WhereOutputRowCount(WhereInfo*);
SQLITE_PRIVATE int sqlite3WhereIsDistinct(WhereInfo*);
SQLITE_PRIVATE int sqlite3WhereIsOrdered(WhereInfo*);
SQLITE_PRIVATE int sqlite3WhereOrderByLimitOptLabel(WhereInfo*);
SQLITE_PRIVATE void sqlite3WhereMinMaxOptEarlyOut(Vdbe*,WhereInfo*);
SQLITE_PRIVATE int sqlite3WhereIsSorted(WhereInfo*);

      **
      ** Always interpret the prior number as a julian-day value.  If this
      ** is not the first modifier, or if the prior argument is not a numeric
      ** value in the allowed range of julian day numbers understood by
      ** SQLite (0..5373484.5) then the result will be NULL.
      */
      if( sqlite3_stricmp(z, "julianday")==0 ){
        if( idx>1 ) return 1;  /* IMP: R-31176-64601 */
        if( p->validJD && p->rawS ){
          rc = 0;
          p->rawS = 0;
        }
      }
      break;
    }

      /*
      **    unixepoch
      **
      ** Treat the current value of p->s as the number of
      ** seconds since 1970.  Convert to a real julian day number.
      */
      if( sqlite3_stricmp(z, "unixepoch")==0 && p->rawS ){
        if( idx>1 ) return 1;  /* IMP: R-49255-55373 */
        r = p->s*1000.0 + 210866760000000.0;
        if( r>=0.0 && r<464269060800000.0 ){
          clearYMD_HMS_TZ(p);
          p->iJD = (sqlite3_int64)(r + 0.5);
          p->validJD = 1;
          p->rawS = 0;
          rc = 0;

*/
static Btree *findBtree(sqlite3 *pErrorDb, sqlite3 *pDb, const char *zDb){
  int i = sqlite3FindDbName(pDb, zDb);

  if( i==1 ){
    Parse sParse;
    int rc = 0;
    sqlite3ParseObjectInit(&sParse,pDb);
    if( sqlite3OpenTempDatabase(&sParse) ){
      sqlite3ErrorWithMsg(pErrorDb, sParse.rc, "%s", sParse.zErrMsg);
      rc = SQLITE_ERROR;
    }
    sqlite3DbFree(pErrorDb, sParse.zErrMsg);
    sqlite3ParseObjectReset(&sParse);
    if( rc ){

  sqlite3_value *pVal = 0;
  int negInt = 1;
  const char *zNeg = "";
  int rc = SQLITE_OK;

  assert( pExpr!=0 );
  while( (op = pExpr->op)==TK_UPLUS || op==TK_SPAN ) pExpr = pExpr->pLeft;

  if( op==TK_REGISTER ) op = pExpr->op2;




  /* Compressed expressions only appear when parsing the DEFAULT clause
  ** on a table column definition, and hence only when pCtx==0.  This
  ** check ensures that an EP_TokenOnly expression is never passed down
  ** into valueFromFunction(). */
  assert( (pExpr->flags & EP_TokenOnly)==0 || pCtx==0 );

    ** to be deleted, based on the WHERE clause. Set variable eOnePass
    ** to indicate the strategy used to implement this delete:
    **
    **  ONEPASS_OFF:    Two-pass approach - use a FIFO for rowids/PK values.
    **  ONEPASS_SINGLE: One-pass approach - at most one row deleted.
    **  ONEPASS_MULTI:  One-pass approach - any number of rows may be deleted.
    */
    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0,0,wcf,iTabCur+1);
    if( pWInfo==0 ) goto delete_from_cleanup;
    eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
    assert( IsVirtual(pTab)==0 || eOnePass!=ONEPASS_MULTI );
    assert( IsVirtual(pTab) || bComplex || eOnePass!=ONEPASS_OFF );
    if( eOnePass!=ONEPASS_SINGLE ) sqlite3MultiWrite(pParse);
    if( sqlite3WhereUsesDeferredSeek(pWInfo) ){
      sqlite3VdbeAddOp1(v, OP_FinishSeek, iTabCur);

  sNameContext.pParse = pParse;
  sqlite3ResolveExprNames(&sNameContext, pWhere);

  /* Create VDBE to loop through the entries in pSrc that match the WHERE
  ** clause. For each row found, increment either the deferred or immediate
  ** foreign key constraint counter. */
  if( pParse->nErr==0 ){
    pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0, 0, 0, 0, 0);
    sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
    if( pWInfo ){
      sqlite3WhereEnd(pWInfo);
    }
  }

  /* Clean up the WHERE clause constructed above. */

SQLITE_PRIVATE void sqlite3ParseObjectInit(Parse *pParse, sqlite3 *db){
  memset(PARSE_HDR(pParse), 0, PARSE_HDR_SZ);
  memset(PARSE_TAIL(pParse), 0, PARSE_TAIL_SZ);
  assert( db->pParse!=pParse );
  pParse->pOuterParse = db->pParse;
  db->pParse = pParse;
  pParse->db = db;
  if( db->mallocFailed ) sqlite3ErrorMsg(pParse, "out of memory");
}

/*
** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
*/
static int sqlite3Prepare(
  sqlite3 *db,              /* Database handle. */

  memset(PARSE_HDR(&sParse), 0, PARSE_HDR_SZ);
  memset(PARSE_TAIL(&sParse), 0, PARSE_TAIL_SZ);
  sParse.pOuterParse = db->pParse;
  db->pParse = &sParse;
  sParse.db = db;
  sParse.pReprepare = pReprepare;
  assert( ppStmt && *ppStmt==0 );
  if( db->mallocFailed ) sqlite3ErrorMsg(&sParse, "out of memory");
  assert( sqlite3_mutex_held(db->mutex) );

  /* For a long-term use prepared statement avoid the use of
  ** lookaside memory.
  */
  if( prepFlags & SQLITE_PREPARE_PERSISTENT ){
    sParse.disableLookaside++;

#endif
    assert( WHERE_USE_LIMIT==SF_FixedLimit );


    /* Begin the database scan. */
    SELECTTRACE(1,pParse,p,("WhereBegin\n"));
    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, sSort.pOrderBy,
                               p->pEList, p, wctrlFlags, p->nSelectRow);
    if( pWInfo==0 ) goto select_end;
    if( sqlite3WhereOutputRowCount(pWInfo) < p->nSelectRow ){
      p->nSelectRow = sqlite3WhereOutputRowCount(pWInfo);
    }
    if( sDistinct.isTnct && sqlite3WhereIsDistinct(pWInfo) ){
      sDistinct.eTnctType = sqlite3WhereIsDistinct(pWInfo);
    }

      ** This might involve two separate loops with an OP_Sort in between, or
      ** it might be a single loop that uses an index to extract information
      ** in the right order to begin with.
      */
      sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
      SELECTTRACE(1,pParse,p,("WhereBegin\n"));
      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pGroupBy, pDistinct,
          0, (WHERE_GROUPBY|(orderByGrp ? WHERE_SORTBYGROUP : 0)|distFlag), 0
      );
      if( pWInfo==0 ){
        sqlite3ExprListDelete(db, pDistinct);
        goto select_end;
      }
      eDist = sqlite3WhereIsDistinct(pWInfo);
      SELECTTRACE(1,pParse,p,("WhereBegin returns\n"));

        ** be an appropriate ORDER BY expression for the optimization.
        */
        assert( minMaxFlag==WHERE_ORDERBY_NORMAL || pMinMaxOrderBy!=0 );
        assert( pMinMaxOrderBy==0 || pMinMaxOrderBy->nExpr==1 );

        SELECTTRACE(1,pParse,p,("WhereBegin\n"));
        pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pMinMaxOrderBy,
                                   pDistinct, 0, minMaxFlag|distFlag, 0);
        if( pWInfo==0 ){
          goto select_end;
        }
        SELECTTRACE(1,pParse,p,("WhereBegin returns\n"));
        eDist = sqlite3WhereIsDistinct(pWInfo);
        updateAccumulator(pParse, regAcc, pAggInfo, eDist);
        if( eDist!=WHERE_DISTINCT_NOOP ){

      ** be deleted as a result of REPLACE conflict handling. Any of these
      ** things might disturb a cursor being used to scan through the table
      ** or index, causing a single-pass approach to malfunction.  */
      flags = WHERE_ONEPASS_DESIRED;
      if( !pParse->nested && !pTrigger && !hasFK && !chngKey && !bReplace ){
        flags |= WHERE_ONEPASS_MULTIROW;
      }
      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere,0,0,0,flags,iIdxCur);
      if( pWInfo==0 ) goto update_cleanup;

      /* A one-pass strategy that might update more than one row may not
      ** be used if any column of the index used for the scan is being
      ** updated. Otherwise, if there is an index on "b", statements like
      ** the following could create an infinite loop:
      **

    sqlite3ExprListDelete(db, pList);
    eOnePass = ONEPASS_OFF;
  }else{
    regRec = ++pParse->nMem;
    regRowid = ++pParse->nMem;

    /* Start scanning the virtual table */
    pWInfo = sqlite3WhereBegin(
        pParse, pSrc, pWhere, 0, 0, 0, WHERE_ONEPASS_DESIRED, 0
    );
    if( pWInfo==0 ) return;

    /* Populate the argument registers. */
    for(i=0; i<pTab->nCol; i++){
      assert( (pTab->aCol[i].colFlags & COLFLAG_GENERATED)==0 );
      if( aXRef[i]>=0 ){
        sqlite3ExprCode(pParse, pChanges->a[aXRef[i]].pExpr, regArg+2+i);

      u16 nBtm;              /* Size of BTM vector */
      u16 nTop;              /* Size of TOP vector */
      u16 nDistinctCol;      /* Index columns used to sort for DISTINCT */
      Index *pIndex;         /* Index used, or NULL */
    } btree;
    struct {               /* Information for virtual tables */
      int idxNum;            /* Index number */
      u8 needFree : 1;       /* True if sqlite3_free(idxStr) is needed */
      u8 bOmitOffset : 1;    /* True to let virtual table handle offset */
      i8 isOrdered;          /* True if satisfies ORDER BY */
      u16 omitMask;          /* Terms that may be omitted */
      char *idxStr;          /* Index identifier string */
    } vtab;
  } u;
  u32 wsFlags;          /* WHERE_* flags describing the plan */
  u16 nLTerm;           /* Number of entries in aLTerm[] */

*/
struct WhereInfo {
  Parse *pParse;            /* Parsing and code generating context */
  SrcList *pTabList;        /* List of tables in the join */
  ExprList *pOrderBy;       /* The ORDER BY clause or NULL */
  ExprList *pResultSet;     /* Result set of the query */
  Expr *pWhere;             /* The complete WHERE clause */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  Select *pLimit;           /* Used to access LIMIT expr/registers for vtabs */
#endif
  int aiCurOnePass[2];      /* OP_OpenWrite cursors for the ONEPASS opt */
  int iContinue;            /* Jump here to continue with next record */
  int iBreak;               /* Jump here to break out of the loop */
  int savedNQueryLoop;      /* pParse->nQueryLoop outside the WHERE loop */
  u16 wctrlFlags;           /* Flags originally passed to sqlite3WhereBegin() */
  LogEst iLimit;            /* LIMIT if wctrlFlags has WHERE_USE_LIMIT */
  u8 nLevel;                /* Number of nested loop */

  Bitmask notReady     /* Which tables are currently available */
);

/* whereexpr.c: */
SQLITE_PRIVATE void sqlite3WhereClauseInit(WhereClause*,WhereInfo*);
SQLITE_PRIVATE void sqlite3WhereClauseClear(WhereClause*);
SQLITE_PRIVATE void sqlite3WhereSplit(WhereClause*,Expr*,u8);
SQLITE_PRIVATE void sqlite3WhereAddLimit(WhereClause*, Select*);
SQLITE_PRIVATE Bitmask sqlite3WhereExprUsage(WhereMaskSet*, Expr*);
SQLITE_PRIVATE Bitmask sqlite3WhereExprUsageNN(WhereMaskSet*, Expr*);
SQLITE_PRIVATE Bitmask sqlite3WhereExprListUsage(WhereMaskSet*, ExprList*);
SQLITE_PRIVATE void sqlite3WhereExprAnalyze(SrcList*, WhereClause*);
SQLITE_PRIVATE void sqlite3WhereTabFuncArgs(Parse*, SrcItem*, WhereClause*);

#define WHERE_PARTIALIDX   0x00020000  /* The automatic index is partial */
#define WHERE_IN_EARLYOUT  0x00040000  /* Perhaps quit IN loops early */
#define WHERE_BIGNULL_SORT 0x00080000  /* Column nEq of index is BIGNULL */
#define WHERE_IN_SEEKSCAN  0x00100000  /* Seek-scan optimization for IN */
#define WHERE_TRANSCONS    0x00200000  /* Uses a transitive constraint */
#define WHERE_BLOOMFILTER  0x00400000  /* Consider using a Bloom-filter */
#define WHERE_SELFCULL     0x00800000  /* nOut reduced by extra WHERE terms */
#define WHERE_OMIT_OFFSET  0x01000000  /* Set offset counter to zero */

#endif /* !defined(SQLITE_WHEREINT_H) */

/************** End of whereInt.h ********************************************/
/************** Continuing where we left off in wherecode.c ******************/

#ifndef SQLITE_OMIT_EXPLAIN

      if( NEVER(pTerm==0) ) continue;
      if( pTerm->eOperator & WO_IN ){
        codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget);
        addrNotFound = pLevel->addrNxt;
      }else{
        Expr *pRight = pTerm->pExpr->pRight;
        codeExprOrVector(pParse, pRight, iTarget, 1);
        if( pTerm->eMatchOp==SQLITE_INDEX_CONSTRAINT_OFFSET
         && pLoop->u.vtab.bOmitOffset
        ){
          assert( pTerm->eOperator==WO_AUX );
          assert( pWInfo->pLimit!=0 );
          assert( pWInfo->pLimit->iOffset>0 );
          sqlite3VdbeAddOp2(v, OP_Integer, 0, pWInfo->pLimit->iOffset);
          VdbeComment((v,"Zero OFFSET counter"));
        }
      }
    }
    sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg);
    sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1);
    sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg,
                      pLoop->u.vtab.idxStr,
                      pLoop->u.vtab.needFree ? P4_DYNAMIC : P4_STATIC);

        if( pAndExpr ){
          pAndExpr->pLeft = pOrExpr;
          pOrExpr = pAndExpr;
        }
        /* Loop through table entries that match term pOrTerm. */
        ExplainQueryPlan((pParse, 1, "INDEX %d", ii+1));
        WHERETRACE(0xffff, ("Subplan for OR-clause:\n"));
        pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0, 0,
                                      WHERE_OR_SUBCLAUSE, iCovCur);
        assert( pSubWInfo || pParse->nErr );
        if( pSubWInfo ){
          WhereLoop *pSubLoop;
          int addrExplain = sqlite3WhereExplainOneScan(
              pParse, pOrTab, &pSubWInfo->a[0], 0
          );

  /* If there is a vector == or IS term - e.g. "(a, b) == (?, ?)" - create
  ** new terms for each component comparison - "a = ?" and "b = ?".  The
  ** new terms completely replace the original vector comparison, which is
  ** no longer used.
  **
  ** This is only required if at least one side of the comparison operation
  ** is not a sub-select.
  **
  ** tag-20220128a
  */
  if( (pExpr->op==TK_EQ || pExpr->op==TK_IS)
   && (nLeft = sqlite3ExprVectorSize(pExpr->pLeft))>1
   && sqlite3ExprVectorSize(pExpr->pRight)==nLeft
   && ( (pExpr->pLeft->flags & EP_xIsSelect)==0
     || (pExpr->pRight->flags & EP_xIsSelect)==0)
   && pWC->op==TK_AND
  ){

  if( pE2->op!=op ){
    whereClauseInsert(pWC, pExpr, 0);
  }else{
    sqlite3WhereSplit(pWC, pE2->pLeft, op);
    sqlite3WhereSplit(pWC, pE2->pRight, op);
  }
}

/*
** Add either a LIMIT (if eMatchOp==SQLITE_INDEX_CONSTRAINT_LIMIT) or
** OFFSET (if eMatchOp==SQLITE_INDEX_CONSTRAINT_OFFSET) term to the
** where-clause passed as the first argument. The value for the term
** is found in register iReg.
**
** In the common case where the value is a simple integer
** (example: "LIMIT 5 OFFSET 10") then the expression codes as a
** TK_INTEGER so that it will be available to sqlite3_vtab_rhs_value().
** If not, then it codes as a TK_REGISTER expression.
*/
void whereAddLimitExpr(
  WhereClause *pWC,   /* Add the constraint to this WHERE clause */
  int iReg,           /* Register that will hold value of the limit/offset */
  Expr *pExpr,        /* Expression that defines the limit/offset */
  int iCsr,           /* Cursor to which the constraint applies */
  int eMatchOp        /* SQLITE_INDEX_CONSTRAINT_LIMIT or _OFFSET */
){
  Parse *pParse = pWC->pWInfo->pParse;
  sqlite3 *db = pParse->db;
  Expr *pNew;
  int iVal = 0;

  if( sqlite3ExprIsInteger(pExpr, &iVal) && iVal>=0 ){
    Expr *pVal = sqlite3Expr(db, TK_INTEGER, 0);
    if( pVal==0 ) return;
    ExprSetProperty(pVal, EP_IntValue);
    pVal->u.iValue = iVal;
    pNew = sqlite3PExpr(pParse, TK_MATCH, 0, pVal);
  }else{
    Expr *pVal = sqlite3Expr(db, TK_REGISTER, 0);
    if( pVal==0 ) return;
    pVal->iTable = iReg;
    pNew = sqlite3PExpr(pParse, TK_MATCH, 0, pVal);
  }
  if( pNew ){
    WhereTerm *pTerm;
    int idx;
    idx = whereClauseInsert(pWC, pNew, TERM_DYNAMIC|TERM_VIRTUAL);
    pTerm = &pWC->a[idx];
    pTerm->leftCursor = iCsr;
    pTerm->eOperator = WO_AUX;
    pTerm->eMatchOp = eMatchOp;
  }
}

/*
** Possibly add terms corresponding to the LIMIT and OFFSET clauses of the
** SELECT statement passed as the second argument. These terms are only
** added if:
**
**   1. The SELECT statement has a LIMIT clause, and
**   2. The SELECT statement is not an aggregate or DISTINCT query, and
**   3. The SELECT statement has exactly one object in its from clause, and
**      that object is a virtual table, and
**   4. There are no terms in the WHERE clause that will not be passed
**      to the virtual table xBestIndex method.
**   5. The ORDER BY clause, if any, will be made available to the xBestIndex
**      method.
**
** LIMIT and OFFSET terms are ignored by most of the planner code. They
** exist only so that they may be passed to the xBestIndex method of the
** single virtual table in the FROM clause of the SELECT.
*/
SQLITE_PRIVATE void sqlite3WhereAddLimit(WhereClause *pWC, Select *p){
  assert( p==0 || (p->pGroupBy==0 && (p->selFlags & SF_Aggregate)==0) );
  if( (p && p->pLimit)                                          /* 1 */
   && (p->selFlags & (SF_Distinct|SF_Aggregate))==0             /* 2 */
   && (p->pSrc->nSrc==1 && IsVirtual(p->pSrc->a[0].pTab))       /* 3 */
  ){
    ExprList *pOrderBy = p->pOrderBy;
    int iCsr = p->pSrc->a[0].iCursor;
    int ii;

    /* Check condition (4). Return early if it is not met. */
    for(ii=0; ii<pWC->nTerm; ii++){
      if( pWC->a[ii].wtFlags & TERM_CODED ){
        /* This term is a vector operation that has been decomposed into
        ** other, subsequent terms.  It can be ignored. See tag-20220128a */
        assert( pWC->a[ii].wtFlags & TERM_VIRTUAL );
        assert( pWC->a[ii].eOperator==0 );
        continue;
      }
      if( pWC->a[ii].leftCursor!=iCsr ) return;
    }

    /* Check condition (5). Return early if it is not met. */
    if( pOrderBy ){
      for(ii=0; ii<pOrderBy->nExpr; ii++){
        Expr *pExpr = pOrderBy->a[ii].pExpr;
        if( pExpr->op!=TK_COLUMN ) return;
        if( pExpr->iTable!=iCsr ) return;
        if( pOrderBy->a[ii].sortFlags & KEYINFO_ORDER_BIGNULL ) return;
      }
    }

    /* All conditions are met. Add the terms to the where-clause object. */
    assert( p->pLimit->op==TK_LIMIT );
    whereAddLimitExpr(pWC, p->iLimit, p->pLimit->pLeft,
                      iCsr, SQLITE_INDEX_CONSTRAINT_LIMIT);
    if( p->iOffset>0 ){
      whereAddLimitExpr(pWC, p->iOffset, p->pLimit->pRight,
                        iCsr, SQLITE_INDEX_CONSTRAINT_OFFSET);
    }
  }
}

/*
** Initialize a preallocated WhereClause structure.
*/
SQLITE_PRIVATE void sqlite3WhereClauseInit(
  WhereClause *pWC,        /* The WhereClause to be initialized */
  WhereInfo *pWInfo        /* The WHERE processing context */

    int i;
    /* Verify that every term past pWC->nBase is virtual */
    for(i=pWC->nBase; i<pWC->nTerm; i++){
      assert( (pWC->a[i].wtFlags & TERM_VIRTUAL)!=0 );
    }
#endif
    while(1){
      assert( a->eMatchOp==0 || a->eOperator==WO_AUX );
      if( a->wtFlags & TERM_DYNAMIC ){
        sqlite3ExprDelete(db, a->pExpr);
      }
      if( a->wtFlags & (TERM_ORINFO|TERM_ANDINFO) ){
        if( a->wtFlags & TERM_ORINFO ){
          assert( (a->wtFlags & TERM_ANDINFO)==0 );
          whereOrInfoDelete(db, a->u.pOrInfo);

    }
    pColRef = sqlite3ExprAlloc(pParse->db, TK_COLUMN, 0, 0);
    if( pColRef==0 ) return;
    pColRef->iTable = pItem->iCursor;
    pColRef->iColumn = k++;
    assert( ExprUseYTab(pColRef) );
    pColRef->y.pTab = pTab;
    pItem->colUsed |= sqlite3ExprColUsed(pColRef);
    pRhs = sqlite3PExpr(pParse, TK_UPLUS,
        sqlite3ExprDup(pParse->db, pArgs->a[j].pExpr, 0), 0);
    pTerm = sqlite3PExpr(pParse, TK_EQ, pColRef, pRhs);
    if( pItem->fg.jointype & JT_LEFT ){
      sqlite3SetJoinExpr(pTerm, pItem->iCursor);
    }
    whereClauseInsert(pWC, pTerm, TERM_DYNAMIC);

    pBuilder->pRec = 0;
#endif
  }
  return rc;
}

#ifndef SQLITE_OMIT_VIRTUALTABLE

/*
** Return true if pTerm is a virtual table LIMIT or OFFSET term.
*/
static int isLimitTerm(WhereTerm *pTerm){
  assert( pTerm->eOperator==WO_AUX || pTerm->eMatchOp==0 );
  return pTerm->eMatchOp>=SQLITE_INDEX_CONSTRAINT_LIMIT
      && pTerm->eMatchOp<=SQLITE_INDEX_CONSTRAINT_OFFSET;
}

/*
** Argument pIdxInfo is already populated with all constraints that may
** be used by the virtual table identified by pBuilder->pNew->iTab. This
** function marks a subset of those constraints usable, invokes the
** xBestIndex method and adds the returned plan to pBuilder.
**

static int whereLoopAddVirtualOne(
  WhereLoopBuilder *pBuilder,
  Bitmask mPrereq,                /* Mask of tables that must be used. */
  Bitmask mUsable,                /* Mask of usable tables */
  u16 mExclude,                   /* Exclude terms using these operators */
  sqlite3_index_info *pIdxInfo,   /* Populated object for xBestIndex */
  u16 mNoOmit,                    /* Do not omit these constraints */
  int *pbIn,                      /* OUT: True if plan uses an IN(...) op */
  int *pbRetryLimit               /* OUT: Retry without LIMIT/OFFSET */
){
  WhereClause *pWC = pBuilder->pWC;
  struct sqlite3_index_constraint *pIdxCons;
  struct sqlite3_index_constraint_usage *pUsage = pIdxInfo->aConstraintUsage;
  int i;
  int mxTerm;
  int rc = SQLITE_OK;

  ** arguments mUsable and mExclude. */
  pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
  for(i=0; i<nConstraint; i++, pIdxCons++){
    WhereTerm *pTerm = &pWC->a[pIdxCons->iTermOffset];
    pIdxCons->usable = 0;
    if( (pTerm->prereqRight & mUsable)==pTerm->prereqRight
     && (pTerm->eOperator & mExclude)==0
     && (pbRetryLimit || !isLimitTerm(pTerm))
    ){
      pIdxCons->usable = 1;
    }
  }

  /* Initialize the output fields of the sqlite3_index_info structure */
  memset(pUsage, 0, sizeof(pUsage[0])*nConstraint);

      return SQLITE_OK;
    }
    return rc;
  }

  mxTerm = -1;
  assert( pNew->nLSlot>=nConstraint );
  memset(pNew->aLTerm, 0, sizeof(pNew->aLTerm[0])*nConstraint );
  memset(&pNew->u.vtab, 0, sizeof(pNew->u.vtab));
  pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
  for(i=0; i<nConstraint; i++, pIdxCons++){
    int iTerm;
    if( (iTerm = pUsage[i].argvIndex - 1)>=0 ){
      WhereTerm *pTerm;
      int j = pIdxCons->iTermOffset;
      if( iTerm>=nConstraint

      if( pUsage[i].omit ){
        if( i<16 && ((1<<i)&mNoOmit)==0 ){
          testcase( i!=iTerm );
          pNew->u.vtab.omitMask |= 1<<iTerm;
        }else{
          testcase( i!=iTerm );
        }
        if( pTerm->eMatchOp==SQLITE_INDEX_CONSTRAINT_OFFSET ){
          pNew->u.vtab.bOmitOffset = 1;
        }
      }
      if( (pTerm->eOperator & WO_IN)!=0 ){
        /* A virtual table that is constrained by an IN clause may not
        ** consume the ORDER BY clause because (1) the order of IN terms
        ** is not necessarily related to the order of output terms and
        ** (2) Multiple outputs from a single IN value will not merge
        ** together.  */
        pIdxInfo->orderByConsumed = 0;
        pIdxInfo->idxFlags &= ~SQLITE_INDEX_SCAN_UNIQUE;
        *pbIn = 1; assert( (mExclude & WO_IN)==0 );
      }

      if( isLimitTerm(pTerm) && *pbIn ){
        /* If there is an IN(...) term handled as an == (separate call to
        ** xFilter for each value on the RHS of the IN) and a LIMIT or
        ** OFFSET term handled as well, the plan is unusable. Set output
        ** variable *pbRetryLimit to true to tell the caller to retry with
        ** LIMIT and OFFSET disabled. */
        if( pIdxInfo->needToFreeIdxStr ){
          sqlite3_free(pIdxInfo->idxStr);
          pIdxInfo->idxStr = 0;
          pIdxInfo->needToFreeIdxStr = 0;
        }
        *pbRetryLimit = 1;
        return SQLITE_OK;
      }
    }
  }

  pNew->nLTerm = mxTerm+1;
  for(i=0; i<=mxTerm; i++){
    if( pNew->aLTerm[i]==0 ){
      /* The non-zero argvIdx values must be contiguous.  Raise an

  SrcItem *pSrc;               /* The FROM clause term to search */
  sqlite3_index_info *p;       /* Object to pass to xBestIndex() */
  int nConstraint;             /* Number of constraints in p */
  int bIn;                     /* True if plan uses IN(...) operator */
  WhereLoop *pNew;
  Bitmask mBest;               /* Tables used by best possible plan */
  u16 mNoOmit;
  int bRetry = 0;              /* True to retry with LIMIT/OFFSET disabled */

  assert( (mPrereq & mUnusable)==0 );
  pWInfo = pBuilder->pWInfo;
  pParse = pWInfo->pParse;
  pWC = pBuilder->pWC;
  pNew = pBuilder->pNew;
  pSrc = &pWInfo->pTabList->a[pNew->iTab];

    freeIndexInfo(pParse->db, p);
    return SQLITE_NOMEM_BKPT;
  }

  /* First call xBestIndex() with all constraints usable. */
  WHERETRACE(0x800, ("BEGIN %s.addVirtual()\n", pSrc->pTab->zName));
  WHERETRACE(0x40, ("  VirtualOne: all usable\n"));
  rc = whereLoopAddVirtualOne(
      pBuilder, mPrereq, ALLBITS, 0, p, mNoOmit, &bIn, &bRetry
  );
  if( bRetry ){
    assert( rc==SQLITE_OK );
    rc = whereLoopAddVirtualOne(
        pBuilder, mPrereq, ALLBITS, 0, p, mNoOmit, &bIn, 0
    );
  }

  /* If the call to xBestIndex() with all terms enabled produced a plan
  ** that does not require any source tables (IOW: a plan with mBest==0)
  ** and does not use an IN(...) operator, then there is no point in making
  ** any further calls to xBestIndex() since they will all return the same
  ** result (if the xBestIndex() implementation is sane). */
  if( rc==SQLITE_OK && ((mBest = (pNew->prereq & ~mPrereq))!=0 || bIn) ){
    int seenZero = 0;             /* True if a plan with no prereqs seen */
    int seenZeroNoIN = 0;         /* Plan with no prereqs and no IN(...) seen */
    Bitmask mPrev = 0;
    Bitmask mBestNoIn = 0;

    /* If the plan produced by the earlier call uses an IN(...) term, call
    ** xBestIndex again, this time with IN(...) terms disabled. */
    if( bIn ){
      WHERETRACE(0x40, ("  VirtualOne: all usable w/o IN\n"));
      rc = whereLoopAddVirtualOne(
          pBuilder, mPrereq, ALLBITS, WO_IN, p, mNoOmit, &bIn, 0);
      assert( bIn==0 );
      mBestNoIn = pNew->prereq & ~mPrereq;
      if( mBestNoIn==0 ){
        seenZero = 1;
        seenZeroNoIN = 1;
      }
    }

      }
      mPrev = mNext;
      if( mNext==ALLBITS ) break;
      if( mNext==mBest || mNext==mBestNoIn ) continue;
      WHERETRACE(0x40, ("  VirtualOne: mPrev=%04llx mNext=%04llx\n",
                       (sqlite3_uint64)mPrev, (sqlite3_uint64)mNext));
      rc = whereLoopAddVirtualOne(
          pBuilder, mPrereq, mNext|mPrereq, 0, p, mNoOmit, &bIn, 0);
      if( pNew->prereq==mPrereq ){
        seenZero = 1;
        if( bIn==0 ) seenZeroNoIN = 1;
      }
    }

    /* If the calls to xBestIndex() in the above loop did not find a plan
    ** that requires no source tables at all (i.e. one guaranteed to be
    ** usable), make a call here with all source tables disabled */
    if( rc==SQLITE_OK && seenZero==0 ){
      WHERETRACE(0x40, ("  VirtualOne: all disabled\n"));
      rc = whereLoopAddVirtualOne(
          pBuilder, mPrereq, mPrereq, 0, p, mNoOmit, &bIn, 0);
      if( bIn==0 ) seenZeroNoIN = 1;
    }

    /* If the calls to xBestIndex() have so far failed to find a plan
    ** that requires no source tables at all and does not use an IN(...)
    ** operator, make a final call to obtain one here.  */
    if( rc==SQLITE_OK && seenZeroNoIN==0 ){
      WHERETRACE(0x40, ("  VirtualOne: all disabled and w/o IN\n"));
      rc = whereLoopAddVirtualOne(
          pBuilder, mPrereq, mPrereq, WO_IN, p, mNoOmit, &bIn, 0);
    }
  }

  if( p->needToFreeIdxStr ) sqlite3_free(p->idxStr);
  freeIndexInfo(pParse->db, p);
  WHERETRACE(0x800, ("END %s.addVirtual(), rc=%d\n", pSrc->pTab->zName, rc));
  return rc;

*/
SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(
  Parse *pParse,          /* The parser context */
  SrcList *pTabList,      /* FROM clause: A list of all tables to be scanned */
  Expr *pWhere,           /* The WHERE clause */
  ExprList *pOrderBy,     /* An ORDER BY (or GROUP BY) clause, or NULL */
  ExprList *pResultSet,   /* Query result set.  Req'd for DISTINCT */
  Select *pLimit,         /* Use this LIMIT/OFFSET clause, if any */
  u16 wctrlFlags,         /* The WHERE_* flags defined in sqliteInt.h */
  int iAuxArg             /* If WHERE_OR_SUBCLAUSE is set, index cursor number
                          ** If WHERE_USE_LIMIT, then the limit amount */
){
  int nByteWInfo;            /* Num. bytes allocated for WhereInfo struct */
  int nTabList;              /* Number of elements in pTabList */
  WhereInfo *pWInfo;         /* Will become the return value of this function */

  pWInfo->pResultSet = pResultSet;
  pWInfo->aiCurOnePass[0] = pWInfo->aiCurOnePass[1] = -1;
  pWInfo->nLevel = nTabList;
  pWInfo->iBreak = pWInfo->iContinue = sqlite3VdbeMakeLabel(pParse);
  pWInfo->wctrlFlags = wctrlFlags;
  pWInfo->iLimit = iAuxArg;
  pWInfo->savedNQueryLoop = pParse->nQueryLoop;
#ifndef SQLITE_OMIT_VIRTUALTABLE
  pWInfo->pLimit = pLimit;
#endif
  memset(&pWInfo->nOBSat, 0,
         offsetof(WhereInfo,sWC) - offsetof(WhereInfo,nOBSat));
  memset(&pWInfo->a[0], 0, sizeof(WhereLoop)+nTabList*sizeof(WhereLevel));
  assert( pWInfo->eOnePass==ONEPASS_OFF );  /* ONEPASS defaults to OFF */
  pMaskSet = &pWInfo->sMaskSet;
  pMaskSet->n = 0;
  pMaskSet->ix[0] = -99; /* Initialize ix[0] to a value that can never be

      }
    }
  #endif
  }

  /* Analyze all of the subexpressions. */
  sqlite3WhereExprAnalyze(pTabList, &pWInfo->sWC);
  sqlite3WhereAddLimit(&pWInfo->sWC, pLimit);
  if( db->mallocFailed ) goto whereBeginError;

  /* Special case: WHERE terms that do not refer to any tables in the join
  ** (constant expressions). Evaluate each such term, and jump over all the
  ** generated code if the result is not true.
  **
  ** Do not do this if the expression contains non-deterministic functions

static void fts5SourceIdFunc(
  sqlite3_context *pCtx,          /* Function call context */
  int nArg,                       /* Number of args */
  sqlite3_value **apUnused        /* Function arguments */
){
  assert( nArg==0 );
  UNUSED_PARAM2(nArg, apUnused);
  sqlite3_result_text(pCtx, "fts5: 2022-01-31 14:14:29 539cef5214446a7181614793e9cf323e95ba00ba0f888585b14b598dd2ff0808", -1, SQLITE_TRANSIENT);
}

/*
** Return true if zName is the extension on one of the shadow tables used
** by this module.
*/
static int fts5ShadowName(const char *zName){

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.38.0"
#define SQLITE_VERSION_NUMBER 3038000
#define SQLITE_SOURCE_ID      "2022-01-31 14:14:29 539cef5214446a7181614793e9cf323e95ba00ba0f888585b14b598dd2ff0808"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

** sqlite3_value objects and they can be used interchangeably.  However,
** for maximum code portability it is recommended that applications
** still make the distinction between protected and unprotected
** sqlite3_value objects even when not strictly required.
**
** ^The sqlite3_value objects that are passed as parameters into the
** implementation of [application-defined SQL functions] are protected.
** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
** are protected.
** ^The sqlite3_value object returned by
** [sqlite3_column_value()] is unprotected.
** Unprotected sqlite3_value objects may only be used as arguments
** to [sqlite3_result_value()], [sqlite3_bind_value()], and
** [sqlite3_value_dup()].
** The [sqlite3_value_blob | sqlite3_value_type()] family of
** interfaces require protected sqlite3_value objects.

#define SQLITE_INDEX_SCAN_UNIQUE      1     /* Scan visits at most 1 row */

/*
** CAPI3REF: Virtual Table Constraint Operator Codes
**
** These macros define the allowed values for the
** [sqlite3_index_info].aConstraint[].op field.  Each value represents
** an operator that is part of a constraint term in the WHERE clause of
** a query that uses a [virtual table].
**
** ^The left-hand operand of the operator is given by the corresponding
** aConstraint[].iColumn field.  ^An iColumn of -1 indicates the left-hand
** operand is the rowid.
** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
** operators have no left-hand operand, and so for those operators the
** corresponding aConstraint[].iColumn is meaningless and should not be
** used.
**
** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
** value 255 are reserved to represent functions that are overloaded
** by the [xFindFunction|xFindFunction method] of the virtual table
** implementation.
**
** The right-hand operands for each constraint might be accessible using
** the [sqlite3_vtab_rhs_value()] interface.  Usually the right-hand
** operand is only available if it appears as a single constant literal
** in the input SQL.  If the right-hand operand is another column or an
** expression (even a constant expression) or a parameter, then the
** sqlite3_vtab_rhs_value() probably will not be able to extract it.
** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
** and hence calls to sqlite3_vtab_rhs_value() for those operators will
** always return SQLITE_NOTFOUND.
**
** The collating sequence to be used for comparison can be found using
** the [sqlite3_vtab_collation()] interface.  For most real-world virtual
** tables, the collating sequence of constraints does not matter (for example
** because the constraints are numeric) and so the sqlite3_vtab_collation()
** interface is no commonly needed.
*/
#define SQLITE_INDEX_CONSTRAINT_EQ          2
#define SQLITE_INDEX_CONSTRAINT_GT          4
#define SQLITE_INDEX_CONSTRAINT_LE          8
#define SQLITE_INDEX_CONSTRAINT_LT         16
#define SQLITE_INDEX_CONSTRAINT_GE         32
#define SQLITE_INDEX_CONSTRAINT_MATCH      64
#define SQLITE_INDEX_CONSTRAINT_LIKE       65
#define SQLITE_INDEX_CONSTRAINT_GLOB       66
#define SQLITE_INDEX_CONSTRAINT_REGEXP     67
#define SQLITE_INDEX_CONSTRAINT_NE         68
#define SQLITE_INDEX_CONSTRAINT_ISNOT      69
#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL  70
#define SQLITE_INDEX_CONSTRAINT_ISNULL     71
#define SQLITE_INDEX_CONSTRAINT_IS         72
#define SQLITE_INDEX_CONSTRAINT_LIMIT      73
#define SQLITE_INDEX_CONSTRAINT_OFFSET     74
#define SQLITE_INDEX_CONSTRAINT_FUNCTION  150

/*
** CAPI3REF: Register A Virtual Table Implementation
** METHOD: sqlite3
**
** ^These routines are used to register a new [virtual table module] name.
** ^Module names must be registered before

*/
SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);

/*
** CAPI3REF: Determine if a virtual table query is DISTINCT
** METHOD: sqlite3_index_info
**
** This API may only be used from within an [xBestIndex|xBestIndex method]
** of a [virtual table] implementation. The result of calling this
** interface from outside of xBestIndex() is undefined and probably harmful.
**
** ^The sqlite3_vtab_distinct() interface returns an integer that is
** either 0, 1, or 2.  The integer returned by sqlite3_vtab_distinct()
** gives the virtual table additional information about how the query
** planner wants the output to be ordered. As long as the virtual table
** can meet the ordering requirements of the query planner, it may set
** the "orderByConsumed" flag.
**
** <ol><li value="0"><p>
** ^If the sqlite3_vtab_distinct() interface returns 0, that means
** that the query planner needs the virtual table to return all rows in the
** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
** [sqlite3_index_info] object.  This is the default expectation.  If the
** virtual table outputs all rows in sorted order, then it is always safe for
** the xBestIndex method to set the "orderByConsumed" flag, regardless of
** the return value from sqlite3_vtab_distinct().
** <li value="1"><p>
** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
** that the query planner does not need the rows to be returned in sorted order
** as long as all rows with the same values in all columns identified by the
** "aOrderBy" field are adjacent.)^  This mode is used when the query planner
** is doing a GROUP BY.
** <li value="2"><p>
** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
** that the query planner does not need the rows returned in any particular
** order, as long as rows with the same values in all "aOrderBy" columns
** are adjacent.)^  ^(Furthermore, only a single row for each particular
** combination of values in the columns identified by the "aOrderBy" field
** needs to be returned.)^  ^It is always ok for two or more rows with the same
** values in all "aOrderBy" columns to be returned, as long as all such rows
** are adjacent.  ^The virtual table may, if it chooses, omit extra rows
** that have the same value for all columns identified by "aOrderBy".
** ^However omitting the extra rows is optional.
** This mode is used for a DISTINCT query.
** </ol>
**

*/
SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);

/*
** CAPI3REF: Constraint values in xBestIndex()
** METHOD: sqlite3_index_info
**
** This API may only be used from within the [xBestIndex|xBestIndex method]
** of a [virtual table] implementation. The result of calling this interface
** from outside of an xBestIndex method are undefined and probably harmful.
**
** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
** the [xBestIndex] method of a [virtual table] implementation, with P being
** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
** J being a 0-based index into P->aConstraint[], then this routine
** attempts to set *V to the value of the right-hand operand of
** that constraint if the right-hand operand is known.  ^If the
** right-hand operand is not known, then *V is set to a NULL pointer.
** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
** and only if *V is set to a value.  ^The sqlite3_vtab_rhs_value(P,J,V)
** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
** constraint is not available.  ^The sqlite3_vtab_rhs_value() interface
** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if
** something goes wrong.
**
** The sqlite3_vtab_rhs_value() interface is usually only successful if
** the right-hand operand of a constraint is a literal value in the original
** SQL statement.  If the right-hand operand is an expression or a reference
** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
** will probably return [SQLITE_NOTFOUND].
**
** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand.  For such
** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
**
** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
** and remains valid for the duration of the xBestIndex method call.
** ^When xBestIndex returns, the sqlite3_value object returned by
** sqlite3_vtab_rhs_value() is automatically deallocated.
**
** The "_rhs_" in the name of this routine is an appreviation for
** "Right-Hand Side".
*/
SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);

/*
** CAPI3REF: Conflict resolution modes
** KEYWORDS: {conflict resolution mode}
**