**
**     lower('I', 'en_us') -> 'i'
**     lower('I', 'tr_tr') -> 'ı' (small dotless i)
**
** http://www.icu-project.org/userguide/posix.html#case_mappings
*/
static void icuCaseFunc16(sqlite3_context *p, int nArg, sqlite3_value **apArg){
  const UChar *zInput;
  UChar *zOutput = 0;
  int nInput;
  int nOut;
  int cnt;

  UErrorCode status;
  const char *zLocale = 0;

  assert(nArg==1 || nArg==2);

  if( nArg==2 ){
    zLocale = (const char *)sqlite3_value_text(apArg[1]);
  }

  zInput = sqlite3_value_text16(apArg[0]);
  if( !zInput ){
    return;
................................................................................
    if( zNew==0 ){
      sqlite3_free(zOutput);
      sqlite3_result_error_nomem(p);
      return;
    }
    zOutput = zNew;
    status = U_ZERO_ERROR;
    if( sqlite3_user_data(p) ){
      nOut = 2*u_strToUpper(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);
    }else{
      nOut = 2*u_strToLower(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);
    }

    if( !U_SUCCESS(status) ){

      if( status==U_BUFFER_OVERFLOW_ERROR ) continue;
      icuFunctionError(p,



          sqlite3_user_data(p) ? "u_strToUpper" : "u_strToLower", status);

      return;
    }
  }
  sqlite3_result_text16(p, zOutput, nOut, xFree);

}

/*
** Collation sequence destructor function. The pCtx argument points to
** a UCollator structure previously allocated using ucol_open().
*/
static void icuCollationDel(void *pCtx){

**
**     lower('I', 'en_us') -> 'i'
**     lower('I', 'tr_tr') -> 'ı' (small dotless i)
**
** http://www.icu-project.org/userguide/posix.html#case_mappings
*/
static void icuCaseFunc16(sqlite3_context *p, int nArg, sqlite3_value **apArg){
  const UChar *zInput;            /* Pointer to input string */
  UChar *zOutput = 0;             /* Pointer to output buffer */
  int nInput;                     /* Size of utf-16 input string in bytes */
  int nOut;                       /* Size of output buffer in bytes */
  int cnt;
  int bToUpper;                   /* True for toupper(), false for tolower() */
  UErrorCode status;
  const char *zLocale = 0;

  assert(nArg==1 || nArg==2);
  bToUpper = (sqlite3_user_data(p)!=0);
  if( nArg==2 ){
    zLocale = (const char *)sqlite3_value_text(apArg[1]);
  }

  zInput = sqlite3_value_text16(apArg[0]);
  if( !zInput ){
    return;
................................................................................
    if( zNew==0 ){
      sqlite3_free(zOutput);
      sqlite3_result_error_nomem(p);
      return;
    }
    zOutput = zNew;
    status = U_ZERO_ERROR;
    if( bToUpper ){
      nOut = 2*u_strToUpper(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);
    }else{
      nOut = 2*u_strToLower(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);
    }

    if( U_SUCCESS(status) ){
      sqlite3_result_text16(p, zOutput, nOut, xFree);
    }else if( status==U_BUFFER_OVERFLOW_ERROR ){

      assert( cnt==0 );
      continue;
    }else{
      icuFunctionError(p, bToUpper ? "u_strToUpper" : "u_strToLower", status);
    }
    return;
  }


  assert( 0 );     /* Unreachable */
}

/*
** Collation sequence destructor function. The pCtx argument points to
** a UCollator structure previously allocated using ucol_open().
*/
static void icuCollationDel(void *pCtx){

  sqlite3_free(p->aiIndent);
  p->aiIndent = 0;
  p->nIndent = 0;
  p->iIndent = 0;
}

/*
** Execute a statement or set of statements.  Print
** any result rows/columns depending on the current mode
** set via the supplied callback.
**
** This is very similar to SQLite's built-in sqlite3_exec()
** function except it takes a slightly different callback
** and callback data argument.
*/






static int shell_exec(
  sqlite3 *db,                              /* An open database */
  const char *zSql,                         /* SQL to be evaluated */
  int (*xCallback)(void*,int,char**,char**,int*),   /* Callback function */
                                            /* (not the same as sqlite3_exec) */
  ShellState *pArg,                         /* Pointer to ShellState */
  char **pzErrMsg                           /* Error msg written here */
){
  sqlite3_stmt *pStmt = NULL;     /* Statement to execute. */
  int rc = SQLITE_OK;             /* Return Code */
  int rc2;
  const char *zLeftover;          /* Tail of unprocessed SQL */


  if( pzErrMsg ){
    *pzErrMsg = NULL;




  }

  while( zSql[0] && (SQLITE_OK == rc) ){
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zLeftover);
    if( SQLITE_OK != rc ){
      if( pzErrMsg ){
        *pzErrMsg = save_err_msg(db);
      }
    }else{



      if( !pStmt ){
        /* this happens for a comment or white-space */
        zSql = zLeftover;
        while( IsSpace(zSql[0]) ) zSql++;
        continue;
      }

      /* save off the prepared statment handle and reset row count */
      if( pArg ){
        pArg->pStmt = pStmt;
        pArg->cnt = 0;
      }

      /* echo the sql statement if echo on */
      if( pArg && pArg->echoOn ){
        const char *zStmtSql = sqlite3_sql(pStmt);
        utf8_printf(pArg->out, "%s\n", zStmtSql ? zStmtSql : zSql);
      }

      /* Show the EXPLAIN QUERY PLAN if .eqp is on */
      if( pArg && pArg->autoEQP ){
        sqlite3_stmt *pExplain;
        char *zEQP = sqlite3_mprintf("EXPLAIN QUERY PLAN %s",
                                     sqlite3_sql(pStmt));
        rc = sqlite3_prepare_v2(db, zEQP, -1, &pExplain, 0);
        if( rc==SQLITE_OK ){
          while( sqlite3_step(pExplain)==SQLITE_ROW ){
            raw_printf(pArg->out,"--EQP-- %d,",sqlite3_column_int(pExplain, 0));
            raw_printf(pArg->out,"%d,", sqlite3_column_int(pExplain, 1));
            raw_printf(pArg->out,"%d,", sqlite3_column_int(pExplain, 2));
            utf8_printf(pArg->out,"%s\n", sqlite3_column_text(pExplain, 3));
          }
        }
        sqlite3_finalize(pExplain);
        sqlite3_free(zEQP);
      }

      if( pArg ){
        pArg->cMode = pArg->mode;
        if( pArg->autoExplain
         && sqlite3_column_count(pStmt)==8
         && sqlite3_strlike("%EXPLAIN%", sqlite3_sql(pStmt),0)==0
        ){
          pArg->cMode = MODE_Explain;
        }

        /* If the shell is currently in ".explain" mode, gather the extra
        ** data required to add indents to the output.*/
        if( pArg->cMode==MODE_Explain ){
          explain_data_prepare(pArg, pStmt);
        }
      }


      /* perform the first step.  this will tell us if we
      ** have a result set or not and how wide it is.
      */
      rc = sqlite3_step(pStmt);
      /* if we have a result set... */
      if( SQLITE_ROW == rc ){
................................................................................
          }
        }else{
          do{
            rc = sqlite3_step(pStmt);
          } while( rc == SQLITE_ROW );
        }
      }










































































































      explain_data_delete(pArg);

      /* print usage stats if stats on */
      if( pArg && pArg->statsOn ){
        display_stats(db, pArg, 0);
      }

................................................................................
  ".clone NEWDB           Clone data into NEWDB from the existing database\n"
  ".databases             List names and files of attached databases\n"
  ".dbinfo ?DB?           Show status information about the database\n"
  ".dump ?TABLE? ...      Dump the database in an SQL text format\n"
  "                         If TABLE specified, only dump tables matching\n"
  "                         LIKE pattern TABLE.\n"
  ".echo on|off           Turn command echo on or off\n"
  ".eqp on|off            Enable or disable automatic EXPLAIN QUERY PLAN\n"
  ".exit                  Exit this program\n"
  ".explain ?on|off|auto? Turn EXPLAIN output mode on or off or to automatic\n"
  ".fullschema ?--indent? Show schema and the content of sqlite_stat tables\n"
  ".headers on|off        Turn display of headers on or off\n"
  ".help                  Show this message\n"
  ".import FILE TABLE     Import data from FILE into TABLE\n"
  ".indexes ?TABLE?       Show names of all indexes\n"
................................................................................
      raw_printf(stderr, "Usage: .echo on|off\n");
      rc = 1;
    }
  }else

  if( c=='e' && strncmp(azArg[0], "eqp", n)==0 ){
    if( nArg==2 ){



      p->autoEQP = booleanValue(azArg[1]);

    }else{
      raw_printf(stderr, "Usage: .eqp on|off\n");
      rc = 1;
    }
  }else

  if( c=='e' && strncmp(azArg[0], "exit", n)==0 ){
    if( nArg>1 && (rc = (int)integerValue(azArg[1]))!=0 ) exit(rc);
    rc = 2;
................................................................................
    }else{
      rc = 0;
    }
  }else

#if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_SELECTTRACE)
  if( c=='s' && n==11 && strncmp(azArg[0], "selecttrace", n)==0 ){
    extern int sqlite3SelectTrace;
    sqlite3SelectTrace = integerValue(azArg[1]);
  }else
#endif

#if defined(SQLITE_ENABLE_SESSION)
  if( c=='s' && strncmp(azArg[0],"session",n)==0 && n>=3 ){
    OpenSession *pSession = &p->aSession[0];
................................................................................
    }
    x = system(zCmd);
    sqlite3_free(zCmd);
    if( x ) raw_printf(stderr, "System command returns %d\n", x);
  }else

  if( c=='s' && strncmp(azArg[0], "show", n)==0 ){

    int i;
    if( nArg!=1 ){
      raw_printf(stderr, "Usage: .show\n");
      rc = 1;
      goto meta_command_exit;
    }
    utf8_printf(p->out, "%12.12s: %s\n","echo", p->echoOn ? "on" : "off");
    utf8_printf(p->out, "%12.12s: %s\n","eqp", p->autoEQP ? "on" : "off");
    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", p->showHeader ? "on" : "off");
    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);
      raw_printf(p->out, "\n");
    utf8_printf(p->out,"%12.12s: ", "rowseparator");
      output_c_string(p->out, p->rowSeparator);
      raw_printf(p->out, "\n");
    utf8_printf(p->out, "%12.12s: %s\n","stats", p->statsOn ? "on" : "off");
    utf8_printf(p->out, "%12.12s: ", "width");
    for (i=0;i<(int)ArraySize(p->colWidth) && p->colWidth[i] != 0;i++) {
      raw_printf(p->out, "%d ", p->colWidth[i]);
    }
    raw_printf(p->out, "\n");
  }else

................................................................................
        sqlite3_free(zVfsName);
      }
    }
  }else

#if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_WHERETRACE)
  if( c=='w' && strncmp(azArg[0], "wheretrace", n)==0 ){
    extern int sqlite3WhereTrace;
    sqlite3WhereTrace = nArg>=2 ? booleanValue(azArg[1]) : 0xff;
  }else
#endif

  if( c=='w' && strncmp(azArg[0], "width", n)==0 ){
    int j;
    assert( nArg<=ArraySize(azArg) );
................................................................................
      data.showHeader = 1;
    }else if( strcmp(z,"-noheader")==0 ){
      data.showHeader = 0;
    }else if( strcmp(z,"-echo")==0 ){
      data.echoOn = 1;
    }else if( strcmp(z,"-eqp")==0 ){
      data.autoEQP = 1;


    }else if( strcmp(z,"-stats")==0 ){
      data.statsOn = 1;
    }else if( strcmp(z,"-scanstats")==0 ){
      data.scanstatsOn = 1;
    }else if( strcmp(z,"-backslash")==0 ){
      /* Undocumented command-line option: -backslash
      ** Causes C-style backslash escapes to be evaluated in SQL statements

  sqlite3_free(p->aiIndent);
  p->aiIndent = 0;
  p->nIndent = 0;
  p->iIndent = 0;
}

/*
** Disable and restore .wheretrace and .selecttrace settings.






*/
#if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_SELECTTRACE)
extern int sqlite3SelectTrace;
static int savedSelectTrace;
#endif
#if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_WHERETRACE)
extern int sqlite3WhereTrace;
static int savedWhereTrace;
#endif
static void disable_debug_trace_modes(void){
#if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_SELECTTRACE)
  savedSelectTrace = sqlite3SelectTrace;
  sqlite3SelectTrace = 0;
#endif
#if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_WHERETRACE)
  savedWhereTrace = sqlite3WhereTrace;
  sqlite3WhereTrace = 0;
#endif

}
static void restore_debug_trace_modes(void){
#if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_SELECTTRACE)
  sqlite3SelectTrace = savedSelectTrace;
#endif
#if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_WHERETRACE)
  sqlite3WhereTrace = savedWhereTrace;
#endif
}








/*
** Run a prepared statement
*/
static void exec_prepared_stmt(
  ShellState *pArg,                                /* Pointer to ShellState */
  sqlite3_stmt *pStmt,                             /* Statment to run */
  int (*xCallback)(void*,int,char**,char**,int*)   /* Callback function */






































){









  int rc;

  /* perform the first step.  this will tell us if we
  ** have a result set or not and how wide it is.
  */
  rc = sqlite3_step(pStmt);
  /* if we have a result set... */
  if( SQLITE_ROW == rc ){
................................................................................
      }
    }else{
      do{
        rc = sqlite3_step(pStmt);
      } while( rc == SQLITE_ROW );
    }
  }
}

/*
** Execute a statement or set of statements.  Print
** any result rows/columns depending on the current mode
** set via the supplied callback.
**
** This is very similar to SQLite's built-in sqlite3_exec()
** function except it takes a slightly different callback
** and callback data argument.
*/
static int shell_exec(
  sqlite3 *db,                              /* An open database */
  const char *zSql,                         /* SQL to be evaluated */
  int (*xCallback)(void*,int,char**,char**,int*),   /* Callback function */
                                            /* (not the same as sqlite3_exec) */
  ShellState *pArg,                         /* Pointer to ShellState */
  char **pzErrMsg                           /* Error msg written here */
){
  sqlite3_stmt *pStmt = NULL;     /* Statement to execute. */
  int rc = SQLITE_OK;             /* Return Code */
  int rc2;
  const char *zLeftover;          /* Tail of unprocessed SQL */

  if( pzErrMsg ){
    *pzErrMsg = NULL;
  }

  while( zSql[0] && (SQLITE_OK == rc) ){
    static const char *zStmtSql;
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zLeftover);
    if( SQLITE_OK != rc ){
      if( pzErrMsg ){
        *pzErrMsg = save_err_msg(db);
      }
    }else{
      if( !pStmt ){
        /* this happens for a comment or white-space */
        zSql = zLeftover;
        while( IsSpace(zSql[0]) ) zSql++;
        continue;
      }
      zStmtSql = sqlite3_sql(pStmt);
      while( IsSpace(zStmtSql[0]) ) zStmtSql++;

      /* save off the prepared statment handle and reset row count */
      if( pArg ){
        pArg->pStmt = pStmt;
        pArg->cnt = 0;
      }

      /* echo the sql statement if echo on */
      if( pArg && pArg->echoOn ){
        utf8_printf(pArg->out, "%s\n", zStmtSql ? zStmtSql : zSql);
      }

      /* Show the EXPLAIN QUERY PLAN if .eqp is on */
      if( pArg && pArg->autoEQP && sqlite3_strlike("EXPLAIN%",zStmtSql,0)!=0 ){
        sqlite3_stmt *pExplain;
        char *zEQP;
        disable_debug_trace_modes();
        zEQP = sqlite3_mprintf("EXPLAIN QUERY PLAN %s", zStmtSql);
        rc = sqlite3_prepare_v2(db, zEQP, -1, &pExplain, 0);
        if( rc==SQLITE_OK ){
          while( sqlite3_step(pExplain)==SQLITE_ROW ){
            raw_printf(pArg->out,"--EQP-- %d,",sqlite3_column_int(pExplain, 0));
            raw_printf(pArg->out,"%d,", sqlite3_column_int(pExplain, 1));
            raw_printf(pArg->out,"%d,", sqlite3_column_int(pExplain, 2));
            utf8_printf(pArg->out,"%s\n", sqlite3_column_text(pExplain, 3));
          }
        }
        sqlite3_finalize(pExplain);
        sqlite3_free(zEQP);
        if( pArg->autoEQP>=2 ){
          /* Also do an EXPLAIN for ".eqp full" mode */
          zEQP = sqlite3_mprintf("EXPLAIN %s", zStmtSql);
          rc = sqlite3_prepare_v2(db, zEQP, -1, &pExplain, 0);
          if( rc==SQLITE_OK ){
            pArg->cMode = MODE_Explain;
            explain_data_prepare(pArg, pExplain);
            exec_prepared_stmt(pArg, pExplain, xCallback);
            explain_data_delete(pArg);
          }
          sqlite3_finalize(pExplain);
          sqlite3_free(zEQP);
        }
        restore_debug_trace_modes();
      }

      if( pArg ){
        pArg->cMode = pArg->mode;
        if( pArg->autoExplain
         && sqlite3_column_count(pStmt)==8
         && sqlite3_strlike("EXPLAIN%", zStmtSql,0)==0
        ){
          pArg->cMode = MODE_Explain;
        }

        /* If the shell is currently in ".explain" mode, gather the extra
        ** data required to add indents to the output.*/
        if( pArg->cMode==MODE_Explain ){
          explain_data_prepare(pArg, pStmt);
        }
      }

      exec_prepared_stmt(pArg, pStmt, xCallback);
      explain_data_delete(pArg);

      /* print usage stats if stats on */
      if( pArg && pArg->statsOn ){
        display_stats(db, pArg, 0);
      }

................................................................................
  ".clone NEWDB           Clone data into NEWDB from the existing database\n"
  ".databases             List names and files of attached databases\n"
  ".dbinfo ?DB?           Show status information about the database\n"
  ".dump ?TABLE? ...      Dump the database in an SQL text format\n"
  "                         If TABLE specified, only dump tables matching\n"
  "                         LIKE pattern TABLE.\n"
  ".echo on|off           Turn command echo on or off\n"
  ".eqp on|off|full       Enable or disable automatic EXPLAIN QUERY PLAN\n"
  ".exit                  Exit this program\n"
  ".explain ?on|off|auto? Turn EXPLAIN output mode on or off or to automatic\n"
  ".fullschema ?--indent? Show schema and the content of sqlite_stat tables\n"
  ".headers on|off        Turn display of headers on or off\n"
  ".help                  Show this message\n"
  ".import FILE TABLE     Import data from FILE into TABLE\n"
  ".indexes ?TABLE?       Show names of all indexes\n"
................................................................................
      raw_printf(stderr, "Usage: .echo on|off\n");
      rc = 1;
    }
  }else

  if( c=='e' && strncmp(azArg[0], "eqp", n)==0 ){
    if( nArg==2 ){
      if( strcmp(azArg[1],"full")==0 ){
        p->autoEQP = 2;
      }else{
        p->autoEQP = booleanValue(azArg[1]);
      }
    }else{
      raw_printf(stderr, "Usage: .eqp on|off|full\n");
      rc = 1;
    }
  }else

  if( c=='e' && strncmp(azArg[0], "exit", n)==0 ){
    if( nArg>1 && (rc = (int)integerValue(azArg[1]))!=0 ) exit(rc);
    rc = 2;
................................................................................
    }else{
      rc = 0;
    }
  }else

#if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_SELECTTRACE)
  if( c=='s' && n==11 && strncmp(azArg[0], "selecttrace", n)==0 ){

    sqlite3SelectTrace = integerValue(azArg[1]);
  }else
#endif

#if defined(SQLITE_ENABLE_SESSION)
  if( c=='s' && strncmp(azArg[0],"session",n)==0 && n>=3 ){
    OpenSession *pSession = &p->aSession[0];
................................................................................
    }
    x = system(zCmd);
    sqlite3_free(zCmd);
    if( x ) raw_printf(stderr, "System command returns %d\n", x);
  }else

  if( c=='s' && strncmp(azArg[0], "show", n)==0 ){
    static const char *azBool[] = { "off", "on", "full", "unk" };
    int i;
    if( nArg!=1 ){
      raw_printf(stderr, "Usage: .show\n");
      rc = 1;
      goto meta_command_exit;
    }
    utf8_printf(p->out, "%12.12s: %s\n","echo", azBool[p->echoOn!=0]);
    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]);
    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);
      raw_printf(p->out, "\n");
    utf8_printf(p->out,"%12.12s: ", "rowseparator");
      output_c_string(p->out, p->rowSeparator);
      raw_printf(p->out, "\n");
    utf8_printf(p->out, "%12.12s: %s\n","stats", azBool[p->statsOn!=0]);
    utf8_printf(p->out, "%12.12s: ", "width");
    for (i=0;i<(int)ArraySize(p->colWidth) && p->colWidth[i] != 0;i++) {
      raw_printf(p->out, "%d ", p->colWidth[i]);
    }
    raw_printf(p->out, "\n");
  }else

................................................................................
        sqlite3_free(zVfsName);
      }
    }
  }else

#if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_WHERETRACE)
  if( c=='w' && strncmp(azArg[0], "wheretrace", n)==0 ){

    sqlite3WhereTrace = nArg>=2 ? booleanValue(azArg[1]) : 0xff;
  }else
#endif

  if( c=='w' && strncmp(azArg[0], "width", n)==0 ){
    int j;
    assert( nArg<=ArraySize(azArg) );
................................................................................
      data.showHeader = 1;
    }else if( strcmp(z,"-noheader")==0 ){
      data.showHeader = 0;
    }else if( strcmp(z,"-echo")==0 ){
      data.echoOn = 1;
    }else if( strcmp(z,"-eqp")==0 ){
      data.autoEQP = 1;
    }else if( strcmp(z,"-eqpfull")==0 ){
      data.autoEQP = 2;
    }else if( strcmp(z,"-stats")==0 ){
      data.statsOn = 1;
    }else if( strcmp(z,"-scanstats")==0 ){
      data.scanstatsOn = 1;
    }else if( strcmp(z,"-backslash")==0 ){
      /* Undocumented command-line option: -backslash
      ** Causes C-style backslash escapes to be evaluated in SQL statements