SQLite

  }
  pDb = &db->aDb[iDb];

  assert( pTab!=0 );
  assert( pParse->nErr==0 );
  if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 
       && db->init.busy==0
       && pTblName!=0
#if SQLITE_USER_AUTHENTICATION
       && sqlite3UserAuthTable(pTab->zName)==0
#endif
#ifdef SQLITE_ALLOW_SQLITE_MASTER_INDEX
       && sqlite3StrICmp(&pTab->zName[7],"master")!=0
#endif
       && sqlite3StrNICmp(&pTab->zName[7],"altertab_",9)!=0

        { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },
        { SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, SQLITE_LoadExtension  },
        { SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE,      SQLITE_NoCkptOnClose  },
        { SQLITE_DBCONFIG_ENABLE_QPSG,           SQLITE_EnableQPSG     },
        { SQLITE_DBCONFIG_TRIGGER_EQP,           SQLITE_TriggerEQP     },
        { SQLITE_DBCONFIG_RESET_DATABASE,        SQLITE_ResetDatabase  },
        { SQLITE_DBCONFIG_DEFENSIVE,             SQLITE_Defensive      },
        { SQLITE_DBCONFIG_WRITABLE_SCHEMA,       SQLITE_WriteSchema|
                                                 SQLITE_NoSchemaError  },
      };
      unsigned int i;
      rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
      for(i=0; i<ArraySize(aFlagOp); i++){
        if( aFlagOp[i].op==op ){
          int onoff = va_arg(ap, int);
          int *pRes = va_arg(ap, int*);

#endif
#if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_WHERETRACE)
  sqlite3WhereTrace = savedWhereTrace;
#endif
}

/* Name of the TEMP table that holds bind parameter values */
#define BIND_PARAM_TABLE "sqlite_parameters"

/* Create the TEMP table used to store parameter bindings */
static void bind_table_init(ShellState *p){
  int wrSchema = 0;
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, -1, &wrSchema);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, 1, 0);
  sqlite3_exec(p->db,
    "CREATE TABLE IF NOT EXISTS temp." BIND_PARAM_TABLE "(\n"
    "  key TEXT PRIMARY KEY,\n"
    "  value ANY\n"
    ") WITHOUT ROWID;",
    0, 0, 0);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, wrSchema, 0);
}

/*
** Bind parameters on a prepared statement.
**
** Parameter bindings are taken from a TEMP table of the form:
**

  nVar = sqlite3_bind_parameter_count(pStmt);
  if( nVar==0 ) return;  /* Nothing to do */
  if( sqlite3_table_column_metadata(pArg->db, "TEMP", BIND_PARAM_TABLE,
                                    "key", 0, 0, 0, 0, 0)!=SQLITE_OK ){
    return; /* Parameter table does not exist */
  }
  rc = sqlite3_prepare_v2(pArg->db,
          "SELECT value FROM temp." BIND_PARAM_TABLE
          " WHERE key=?1", -1, &pQ, 0);
  if( rc || pQ==0 ) return;
  for(i=1; i<=nVar; i++){
    char zNum[30];
    const char *zVar = sqlite3_bind_parameter_name(pStmt, i);
    if( zVar==0 ){
      sqlite3_snprintf(sizeof(zNum),zNum,"?%d",i);

    open_db(p,0);
    if( nArg<=1 ) goto parameter_syntax_error;

    /* .parameter clear
    ** Clear all bind parameters by dropping the TEMP table that holds them.
    */
    if( nArg==2 && strcmp(azArg[1],"clear")==0 ){
      int wrSchema = 0;
      sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, -1, &wrSchema);
      sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, 1, 0);
      sqlite3_exec(p->db, "DROP TABLE IF EXISTS temp." BIND_PARAM_TABLE ";",
                   0, 0, 0);
      sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, wrSchema, 0);
    }else

    /* .parameter list
    ** List all bind parameters.
    */
    if( nArg==2 && strcmp(azArg[1],"list")==0 ){
      sqlite3_stmt *pStmt = 0;
      int rx;
      int len = 0;
      rx = sqlite3_prepare_v2(p->db,
             "SELECT max(length(key)) "
             "FROM temp." BIND_PARAM_TABLE ";", -1, &pStmt, 0);
      if( rx==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
        len = sqlite3_column_int(pStmt, 0);
        if( len>40 ) len = 40;
      }
      sqlite3_finalize(pStmt);
      pStmt = 0;
      if( len ){
        rx = sqlite3_prepare_v2(p->db,
             "SELECT key, quote(value) "
             "FROM temp." BIND_PARAM_TABLE ";", -1, &pStmt, 0);
        while( sqlite3_step(pStmt)==SQLITE_ROW ){
          utf8_printf(p->out, "%-*s %s\n", len, sqlite3_column_text(pStmt,0),
                      sqlite3_column_text(pStmt,1));
        }
        sqlite3_finalize(pStmt);
      }
    }else

      int rx;
      char *zSql;
      sqlite3_stmt *pStmt;
      const char *zKey = azArg[2];
      const char *zValue = azArg[3];
      bind_table_init(p);
      zSql = sqlite3_mprintf(
                  "REPLACE INTO temp." BIND_PARAM_TABLE "(key,value)"
                  "VALUES(%Q,%s);", zKey, zValue);
      if( zSql==0 ) shell_out_of_memory();
      pStmt = 0;
      rx = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
      sqlite3_free(zSql);
      if( rx!=SQLITE_OK ){
        sqlite3_finalize(pStmt);
        pStmt = 0;
        zSql = sqlite3_mprintf(
                   "REPLACE INTO temp." BIND_PARAM_TABLE "(key,value)"
                   "VALUES(%Q,%Q);", zKey, zValue);
        if( zSql==0 ) shell_out_of_memory();
        rx = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
        sqlite3_free(zSql);
        if( rx!=SQLITE_OK ){
          utf8_printf(p->out, "Error: %s\n", sqlite3_errmsg(p->db));
          sqlite3_finalize(pStmt);

    /* .parameter unset NAME
    ** Remove the NAME binding from the parameter binding table, if it
    ** exists.
    */
    if( nArg==3 && strcmp(azArg[1],"unset")==0 ){
      char *zSql = sqlite3_mprintf(
          "DELETE FROM temp." BIND_PARAM_TABLE " WHERE key=%Q", azArg[2]);
      if( zSql==0 ) shell_out_of_memory();
      sqlite3_exec(p->db, zSql, 0, 0, 0);
      sqlite3_free(zSql);
    }else
    /* If no command name matches, show a syntax error */
    parameter_syntax_error:
    showHelp(p->out, "parameter");

** features include but are not limited to the following:
** <ul>
** <li> The [PRAGMA writable_schema=ON] statement.
** <li> Writes to the [sqlite_dbpage] virtual table.
** <li> Direct writes to [shadow tables].
** </ul>
** </dd>
**
** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
** "writable_schema" flag. This has the same effect and is logically equivalent
** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
** The first argument to this setting is an integer which is 0 to disable 
** the writable_schema, positive to enable writable_schema, or negative to
** leave the setting unchanged. The second parameter is a pointer to an
** integer into which is written 0 or 1 to indicate whether the writable_schema
** is enabled or disabled following this call.
** </dd>
** </dl>
*/
#define SQLITE_DBCONFIG_MAINDBNAME            1000 /* const char* */
#define SQLITE_DBCONFIG_LOOKASIDE             1001 /* void* int int */
#define SQLITE_DBCONFIG_ENABLE_FKEY           1002 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_TRIGGER        1003 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE      1006 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_QPSG           1007 /* int int* */
#define SQLITE_DBCONFIG_TRIGGER_EQP           1008 /* int int* */
#define SQLITE_DBCONFIG_RESET_DATABASE        1009 /* int int* */
#define SQLITE_DBCONFIG_DEFENSIVE             1010 /* int int* */
#define SQLITE_DBCONFIG_WRITABLE_SCHEMA       1011 /* int int* */
#define SQLITE_DBCONFIG_MAX                   1011 /* Largest DBCONFIG */

/*
** CAPI3REF: Enable Or Disable Extended Result Codes
** METHOD: sqlite3
**
** ^The sqlite3_extended_result_codes() routine enables or disables the
** [extended result codes] feature of SQLite. ^The extended result