SQLite

    if( zWord==0 ){
      /* Inserts of the form:  INSERT INTO table(command) VALUES('xyzzy');
      ** cause zWord to be NULL, so we look at the "command" column to see
      ** what special actions to take */
      const char *zCmd = 
         (const char*)sqlite3_value_text(argv[SPELLFIX_COL_COMMAND+2]);
      if( zCmd==0 ){
        pVTab->zErrMsg = sqlite3_mprintf("NOT NULL constraint failed: %s.word",
                                         p->zTableName);
        return SQLITE_CONSTRAINT_NOTNULL;
      }
      if( strcmp(zCmd,"reset")==0 ){
        /* Reset the  edit cost table (if there is one). */
        editDist3ConfigDelete(p->pConfig3);
        p->pConfig3 = 0;

do_eqp_test 2.5 {
  SELECT * FROM t, r_tree
} {
  0 0 1 {SCAN TABLE r_tree VIRTUAL TABLE INDEX 2:}
  0 1 0 {SCAN TABLE t} 
}

#-------------------------------------------------------------------------
# Test that the special CROSS JOIN handling works with rtree tables.
#
do_execsql_test 3.1 {
  CREATE TABLE t1(x);
  CREATE TABLE t2(y);
  CREATE VIRTUAL TABLE t3 USING rtree(z, x1,x2, y1,y2);
}

do_eqp_test 3.2.1 { SELECT * FROM t1 CROSS JOIN t2 } {
  0 0 0 {SCAN TABLE t1} 
  0 1 1 {SCAN TABLE t2}
}
do_eqp_test 3.2.2 { SELECT * FROM t2 CROSS JOIN t1 } {
  0 0 0 {SCAN TABLE t2} 0 1 1 {SCAN TABLE t1}
}

do_eqp_test 3.3.1 { SELECT * FROM t1 CROSS JOIN t3 } {
  0 0 0 {SCAN TABLE t1}
  0 1 1 {SCAN TABLE t3 VIRTUAL TABLE INDEX 2:} 
}
do_eqp_test 3.3.2 { SELECT * FROM t3 CROSS JOIN t1 } {
  0 0 0 {SCAN TABLE t3 VIRTUAL TABLE INDEX 2:} 
  0 1 1 {SCAN TABLE t1}
}

#--------------------------------------------------------------------
# Test that LEFT JOINs are not reordered if the right-hand-side is
# a virtual table.
#
reset_db
do_execsql_test 4.1 {
  CREATE TABLE t1(a);
  CREATE VIRTUAL TABLE t2 USING rtree(b, x1,x2);

  INSERT INTO t1 VALUES(1);
  INSERT INTO t1 VALUES(2);

  INSERT INTO t2 VALUES(1, 0.0, 0.1);
  INSERT INTO t2 VALUES(3, 0.0, 0.1);
}

do_execsql_test 4.2 {
  SELECT a, b FROM t1 LEFT JOIN t2 ON (+a = +b);
} {1 1 2 {}}

do_execsql_test 4.3 {
  SELECT b, a FROM t2 LEFT JOIN t1 ON (+a = +b);
} {1 1 3 {}}

finish_test

        sqlite3CodeVerifySchema(pParse, iDb);
        sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);

        /* Search for the index that has the lowest scan cost.
        **
        ** (2011-04-15) Do not do a full scan of an unordered index.
        **
        ** (2013-10-03) Do not count the entries in a partial index.
        **
        ** In practice the KeyInfo structure will not be used. It is only 
        ** passed to keep OP_OpenRead happy.
        */
        if( !HasRowid(pTab) ) pBest = sqlite3PrimaryKeyIndex(pTab);
        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
          if( pIdx->bUnordered==0
           && pIdx->szIdxRow<pTab->szTabRow
           && pIdx->pPartIdxWhere==0
           && (!pBest || pIdx->szIdxRow<pBest->szIdxRow)
          ){
            pBest = pIdx;

    unsigned char omit;      /* Do not code a test for this constraint */
  } *aConstraintUsage;
  int idxNum;                /* Number used to identify the index */
  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
  int orderByConsumed;       /* True if output is already ordered */
  double estimatedCost;           /* Estimated cost of using this index */
  /* Fields below are only available in SQLite 3.8.2 and later */
  sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */
};

/*
** CAPI3REF: Virtual Table Constraint Operator Codes
**
** These macros defined the allowed values for the

#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Add all WhereLoop objects for a table of the join identified by
** pBuilder->pNew->iTab.  That table is guaranteed to be a virtual table.
*/
static int whereLoopAddVirtual(
  WhereLoopBuilder *pBuilder,  /* WHERE clause information */
  Bitmask mExtra
){
  WhereInfo *pWInfo;           /* WHERE analysis context */
  Parse *pParse;               /* The parsing context */
  WhereClause *pWC;            /* The WHERE clause */
  struct SrcList_item *pSrc;   /* The FROM clause term to search */
  Table *pTab;
  sqlite3 *db;

    pIdxInfo->needToFreeIdxStr = 0;
    pIdxInfo->orderByConsumed = 0;
    pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;
    pIdxInfo->estimatedRows = 25;
    rc = vtabBestIndex(pParse, pTab, pIdxInfo);
    if( rc ) goto whereLoopAddVtab_exit;
    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
    pNew->prereq = mExtra;
    mxTerm = -1;
    assert( pNew->nLSlot>=nConstraint );
    for(i=0; i<nConstraint; i++) pNew->aLTerm[i] = 0;
    pNew->u.vtab.omitMask = 0;
    for(i=0; i<nConstraint; i++, pIdxCons++){
      if( (iTerm = pUsage[i].argvIndex - 1)>=0 ){
        j = pIdxCons->iTermOffset;

          sSubBuild.pWC = &tempWC;
        }else{
          continue;
        }
        sCur.n = 0;
#ifndef SQLITE_OMIT_VIRTUALTABLE
        if( IsVirtual(pItem->pTab) ){
          rc = whereLoopAddVirtual(&sSubBuild, mExtra);

        }else
#endif
        {
          rc = whereLoopAddBtree(&sSubBuild, mExtra);
        }
        assert( rc==SQLITE_OK || sCur.n==0 );
        if( sCur.n==0 ){

    pNew->iTab = iTab;
    pNew->maskSelf = getMask(&pWInfo->sMaskSet, pItem->iCursor);
    if( ((pItem->jointype|priorJoinType) & (JT_LEFT|JT_CROSS))!=0 ){
      mExtra = mPrior;
    }
    priorJoinType = pItem->jointype;
    if( IsVirtual(pItem->pTab) ){
      rc = whereLoopAddVirtual(pBuilder, mExtra);
    }else{
      rc = whereLoopAddBtree(pBuilder, mExtra);
    }
    if( rc==SQLITE_OK ){
      rc = whereLoopAddOr(pBuilder, mExtra);
    }
    mPrior |= pNew->maskSelf;

# 2009-02-24
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing "SELECT count(*)" statements.
#


set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Test plan:
#
#  count-0.*: Make sure count(*) works on an empty database.  (Ticket #3774)
#
#  count-1.*: Test that the OP_Count instruction appears to work on both
#             tables and indexes. Test both when they contain 0 entries,
#             when all entries are on the root page, and when the b-tree
#             forms a structure 2 and 3 levels deep.


#
#

do_test count-0.1 {
  db eval {
     SELECT count(*) FROM sqlite_master;
  }

  execsql {
    DROP INDEX t4i1;
    CREATE INDEX t4i1 ON t4(b, a);
    SELECT count(*) FROM t4;
  }
} {1}

do_execsql_test count-5.1 {
  CREATE TABLE t5(a TEXT PRIMARY KEY, b VARCHAR(50)) WITHOUT ROWID;
  INSERT INTO t5 VALUES('bison','jazz');
  SELECT count(*) FROM t5;
} {1}

finish_test

  #
  set R "\033\[31;1m"        ;# Red fg
  set G "\033\[32;1m"        ;# Green fg
  set B "\033\[34;1m"        ;# Red fg
  set D "\033\[39;0m"        ;# Default fg
  foreach opcode {
      Seek SeekGe SeekGt SeekLe SeekLt NotFound Last Rewind
      NoConflict Next Prev VNext VPrev VFilter
  } {
    set color($opcode) $B
  }
  foreach opcode {ResultRow} {
    set color($opcode) $G
  }
  foreach opcode {IdxInsert Insert Delete IdxDelete} {
    set color($opcode) $R
  }

  set bSeenGoto 0
  $db eval "explain $sql" {} {
    set x($addr) 0
    set op($addr) $opcode

    if {$opcode == "Goto" && ($bSeenGoto==0 || ($p2 > $addr+10))} {
      set linebreak($p2) 1
      set bSeenGoto 1
    }

    if {$opcode=="Next"  || $opcode=="Prev" 
     || $opcode=="VNext" || $opcode=="VPrev"
    } {
      for {set i $p2} {$i<$addr} {incr i} {
        incr x($i) 2
      }
    }

    if {$opcode == "Goto" && $p2<$addr && $op($p2)=="Yield"} {
      for {set i [expr $p2+1]} {$i<$addr} {incr i} {