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SQLite training in Houston TX on 2019-11-05 (details)
Part of the 2019 Tcl Conference

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Overview
Comment:Improved optimizations of views as the right operand of a LEFT JOIN.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA3-256: 41c27bc0ff1d3135cdb6273ede4595f5bb0c0e1e1d470ea1633cb525674cf431
User & Date: drh 2017-04-18 11:20:19
References
2017-07-29
03:26 New ticket [de3403bf] Column name shift due to LEFT JOIN query flattening. artifact: e6b7df69 user: drh
2017-06-20
16:15 New ticket [892fc34f] Incorrect query result when a LEFT JOIN subquery is flattened. artifact: d28d6544 user: drh
Context
2017-04-18
13:50
Use sqlite3_table_column_metadata() instead of a SELECT statement to check for the existence of a %_stat table in fts3. This leads to smaller and easier to test code. check-in: dc2a4802 user: dan tags: trunk
11:20
Improved optimizations of views as the right operand of a LEFT JOIN. check-in: 41c27bc0 user: drh tags: trunk
05:49
Refactor the fts3ColumnMethod() function so that all branches can be covered. check-in: e47fdb49 user: dan tags: trunk
2017-04-14
19:03
Add the TK_IF_NULL_ROW opcode to deal with non-NULL result columns in the result set of a view or subquery on the RHS of a LEFT JOIN that gets flattened. Closed-Leaf check-in: 3a5860d8 user: drh tags: left-join-view
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/expr.c.

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      break;
    }

    case TK_VECTOR: {
      sqlite3ErrorMsg(pParse, "row value misused");
      break;
    }












    /*
    ** Form A:
    **   CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
    **
    ** Form B:
    **   CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END







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      break;
    }

    case TK_VECTOR: {
      sqlite3ErrorMsg(pParse, "row value misused");
      break;
    }

    case TK_IF_NULL_ROW: {
      int addrINR;
      addrINR = sqlite3VdbeAddOp1(v, OP_IfNullRow, pExpr->iTable);
      sqlite3ExprCachePush(pParse);
      inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
      sqlite3ExprCachePop(pParse);
      sqlite3VdbeJumpHere(v, addrINR);
      sqlite3VdbeChangeP3(v, addrINR, inReg);
      break;
    }

    /*
    ** Form A:
    **   CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
    **
    ** Form B:
    **   CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END

Changes to src/parse.y.

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    A = 0;
    sqlite3ErrorMsg(pParse, "unknown table option: %.*s", X.n, X.z);
  }
}
columnlist ::= columnlist COMMA columnname carglist.
columnlist ::= columnname carglist.
columnname(A) ::= nm(A) typetoken(Y). {sqlite3AddColumn(pParse,&A,&Y);}


















// Define operator precedence early so that this is the first occurrence
// of the operator tokens in the grammer.  Keeping the operators together
// causes them to be assigned integer values that are close together,
// which keeps parser tables smaller.
//
// The token values assigned to these symbols is determined by the order
................................................................................
%right BITNOT.

// An IDENTIFIER can be a generic identifier, or one of several
// keywords.  Any non-standard keyword can also be an identifier.
//
%token_class id  ID|INDEXED.

// The following directive causes tokens ABORT, AFTER, ASC, etc. to
// fallback to ID if they will not parse as their original value.
// This obviates the need for the "id" nonterminal.
//
%fallback ID
  ABORT ACTION AFTER ANALYZE ASC ATTACH BEFORE BEGIN BY CASCADE CAST COLUMNKW
  CONFLICT DATABASE DEFERRED DESC DETACH EACH END EXCLUSIVE EXPLAIN FAIL FOR
  IGNORE IMMEDIATE INITIALLY INSTEAD LIKE_KW MATCH NO PLAN
  QUERY KEY OF OFFSET PRAGMA RAISE RECURSIVE RELEASE REPLACE RESTRICT ROW
  ROLLBACK SAVEPOINT TEMP TRIGGER VACUUM VIEW VIRTUAL WITH WITHOUT
%ifdef SQLITE_OMIT_COMPOUND_SELECT
  EXCEPT INTERSECT UNION
%endif SQLITE_OMIT_COMPOUND_SELECT
  REINDEX RENAME CTIME_KW IF
  .
%wildcard ANY.


// And "ids" is an identifer-or-string.
//
%token_class ids  ID|STRING.

// The name of a column or table can be any of the following:
//







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    A = 0;
    sqlite3ErrorMsg(pParse, "unknown table option: %.*s", X.n, X.z);
  }
}
columnlist ::= columnlist COMMA columnname carglist.
columnlist ::= columnname carglist.
columnname(A) ::= nm(A) typetoken(Y). {sqlite3AddColumn(pParse,&A,&Y);}

// The following directive causes tokens ABORT, AFTER, ASC, etc. to
// fallback to ID if they will not parse as their original value.
// This obviates the need for the "id" nonterminal.
//
%fallback ID
  ABORT ACTION AFTER ANALYZE ASC ATTACH BEFORE BEGIN BY CASCADE CAST COLUMNKW
  CONFLICT DATABASE DEFERRED DESC DETACH EACH END EXCLUSIVE EXPLAIN FAIL FOR
  IGNORE IMMEDIATE INITIALLY INSTEAD LIKE_KW MATCH NO PLAN
  QUERY KEY OF OFFSET PRAGMA RAISE RECURSIVE RELEASE REPLACE RESTRICT ROW
  ROLLBACK SAVEPOINT TEMP TRIGGER VACUUM VIEW VIRTUAL WITH WITHOUT
%ifdef SQLITE_OMIT_COMPOUND_SELECT
  EXCEPT INTERSECT UNION
%endif SQLITE_OMIT_COMPOUND_SELECT
  REINDEX RENAME CTIME_KW IF
  .
%wildcard ANY.

// Define operator precedence early so that this is the first occurrence
// of the operator tokens in the grammer.  Keeping the operators together
// causes them to be assigned integer values that are close together,
// which keeps parser tables smaller.
//
// The token values assigned to these symbols is determined by the order
................................................................................
%right BITNOT.

// An IDENTIFIER can be a generic identifier, or one of several
// keywords.  Any non-standard keyword can also be an identifier.
//
%token_class id  ID|INDEXED.



















// And "ids" is an identifer-or-string.
//
%token_class ids  ID|STRING.

// The name of a column or table can be any of the following:
//

Changes to src/select.c.

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**
** All references to columns in table iTable are to be replaced by corresponding
** expressions in pEList.
*/
typedef struct SubstContext {
  Parse *pParse;            /* The parsing context */
  int iTable;               /* Replace references to this table */


  ExprList *pEList;         /* Replacement expressions */
} SubstContext;

/* Forward Declarations */
static void substExprList(SubstContext*, ExprList*);
static void substSelect(SubstContext*, Select*, int);

................................................................................
** of the subquery rather the result set of the subquery.
*/
static Expr *substExpr(
  SubstContext *pSubst,  /* Description of the substitution */
  Expr *pExpr            /* Expr in which substitution occurs */
){
  if( pExpr==0 ) return 0;



  if( pExpr->op==TK_COLUMN && pExpr->iTable==pSubst->iTable ){
    if( pExpr->iColumn<0 ){
      pExpr->op = TK_NULL;
    }else{
      Expr *pNew;
      Expr *pCopy = pSubst->pEList->a[pExpr->iColumn].pExpr;

      assert( pSubst->pEList!=0 && pExpr->iColumn<pSubst->pEList->nExpr );
      assert( pExpr->pLeft==0 && pExpr->pRight==0 );
      if( sqlite3ExprIsVector(pCopy) ){
        sqlite3VectorErrorMsg(pSubst->pParse, pCopy);
      }else{
        sqlite3 *db = pSubst->pParse->db;







        pNew = sqlite3ExprDup(db, pCopy, 0);
        if( pNew && (pExpr->flags & EP_FromJoin) ){
          pNew->iRightJoinTable = pExpr->iRightJoinTable;
          pNew->flags |= EP_FromJoin;
        }
        sqlite3ExprDelete(db, pExpr);
        pExpr = pNew;
................................................................................
**   (1)  The subquery and the outer query do not both use aggregates.
**
**   (2)  The subquery is not an aggregate or (2a) the outer query is not a join
**        and (2b) the outer query does not use subqueries other than the one
**        FROM-clause subquery that is a candidate for flattening.  (2b is
**        due to ticket [2f7170d73bf9abf80] from 2015-02-09.)
**
**   (3)  The subquery is not the right operand of a left outer join
**        (Originally ticket #306.  Strengthened by ticket #3300)
**
**   (4)  The subquery is not DISTINCT.
**
**  (**)  At one point restrictions (4) and (5) defined a subset of DISTINCT
**        sub-queries that were excluded from this optimization. Restriction 
**        (4) has since been expanded to exclude all DISTINCT subqueries.
**
**   (6)  The subquery does not use aggregates or the outer query is not
**        DISTINCT.
**
**   (7)  The subquery has a FROM clause.  TODO:  For subqueries without
**        A FROM clause, consider adding a FROM close with the special
**        table sqlite_once that consists of a single row containing a
**        single NULL.
**
**   (8)  The subquery does not use LIMIT or the outer query is not a join.
**
**   (9)  The subquery does not use LIMIT or the outer query does not use
**        aggregates.
................................................................................
  Select *pParent;    /* Current UNION ALL term of the other query */
  Select *pSub;       /* The inner query or "subquery" */
  Select *pSub1;      /* Pointer to the rightmost select in sub-query */
  SrcList *pSrc;      /* The FROM clause of the outer query */
  SrcList *pSubSrc;   /* The FROM clause of the subquery */
  ExprList *pList;    /* The result set of the outer query */
  int iParent;        /* VDBE cursor number of the pSub result set temp table */


  int i;              /* Loop counter */
  Expr *pWhere;                    /* The WHERE clause */
  struct SrcList_item *pSubitem;   /* The subquery */
  sqlite3 *db = pParse->db;

  /* Check to see if flattening is permitted.  Return 0 if not.
  */
................................................................................
    if( (p->pWhere && ExprHasProperty(p->pWhere,EP_Subquery))
     || (sqlite3ExprListFlags(p->pEList) & EP_Subquery)!=0
     || (sqlite3ExprListFlags(p->pOrderBy) & EP_Subquery)!=0
    ){
      return 0;                                          /* Restriction (2b)  */
    }
  }
    
  pSubSrc = pSub->pSrc;
  assert( pSubSrc );
  /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
  ** not arbitrary expressions, we allowed some combining of LIMIT and OFFSET
  ** because they could be computed at compile-time.  But when LIMIT and OFFSET
  ** became arbitrary expressions, we were forced to add restrictions (13)
  ** and (14). */
................................................................................
  if( pSub->selFlags & (SF_Recursive|SF_MinMaxAgg) ){
    return 0; /* Restrictions (22) and (24) */
  }
  if( (p->selFlags & SF_Recursive) && pSub->pPrior ){
    return 0; /* Restriction (23) */
  }

  /* OBSOLETE COMMENT 1:
  ** Restriction 3:  If the subquery is a join, make sure the subquery is 
  ** not used as the right operand of an outer join.  Examples of why this
  ** is not allowed:
  **
  **         t1 LEFT OUTER JOIN (t2 JOIN t3)
  **
  ** If we flatten the above, we would get
  **
  **         (t1 LEFT OUTER JOIN t2) JOIN t3
  **
  ** which is not at all the same thing.
  **
  ** OBSOLETE COMMENT 2:
  ** Restriction 12:  If the subquery is the right operand of a left outer
  ** join, make sure the subquery has no WHERE clause.
  ** An examples of why this is not allowed:
  **
  **         t1 LEFT OUTER JOIN (SELECT * FROM t2 WHERE t2.x>0)
  **
  ** If we flatten the above, we would get
  **
  **         (t1 LEFT OUTER JOIN t2) WHERE t2.x>0
  **
  ** But the t2.x>0 test will always fail on a NULL row of t2, which
  ** effectively converts the OUTER JOIN into an INNER JOIN.
  **
  ** THIS OVERRIDES OBSOLETE COMMENTS 1 AND 2 ABOVE:
  ** Ticket #3300 shows that flattening the right term of a LEFT JOIN
  ** is fraught with danger.  Best to avoid the whole thing.  If the
  ** subquery is the right term of a LEFT JOIN, then do not flatten.
  */
  if( (pSubitem->fg.jointype & JT_OUTER)!=0 ){


    return 0;

  }

  /* Restriction 17: If the sub-query is a compound SELECT, then it must
  ** use only the UNION ALL operator. And none of the simple select queries
  ** that make up the compound SELECT are allowed to be aggregate or distinct
  ** queries.
  */
................................................................................
    /* Transfer the FROM clause terms from the subquery into the
    ** outer query.
    */
    for(i=0; i<nSubSrc; i++){
      sqlite3IdListDelete(db, pSrc->a[i+iFrom].pUsing);
      assert( pSrc->a[i+iFrom].fg.isTabFunc==0 );
      pSrc->a[i+iFrom] = pSubSrc->a[i];

      memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
    }
    pSrc->a[iFrom].fg.jointype = jointype;
  
    /* Now begin substituting subquery result set expressions for 
    ** references to the iParent in the outer query.
    ** 
................................................................................
      }
      assert( pParent->pOrderBy==0 );
      assert( pSub->pPrior==0 );
      pParent->pOrderBy = pOrderBy;
      pSub->pOrderBy = 0;
    }
    pWhere = sqlite3ExprDup(db, pSub->pWhere, 0);



    if( subqueryIsAgg ){
      assert( pParent->pHaving==0 );
      pParent->pHaving = pParent->pWhere;
      pParent->pWhere = pWhere;
      pParent->pHaving = sqlite3ExprAnd(db, 
          sqlite3ExprDup(db, pSub->pHaving, 0), pParent->pHaving
      );
................................................................................
    }else{
      pParent->pWhere = sqlite3ExprAnd(db, pWhere, pParent->pWhere);
    }
    if( db->mallocFailed==0 ){
      SubstContext x;
      x.pParse = pParse;
      x.iTable = iParent;


      x.pEList = pSub->pEList;
      substSelect(&x, pParent, 0);
    }
  
    /* The flattened query is distinct if either the inner or the
    ** outer query is distinct. 
    */
................................................................................
  if( sqlite3ExprIsTableConstant(pWhere, iCursor) ){
    nChng++;
    while( pSubq ){
      SubstContext x;
      pNew = sqlite3ExprDup(pParse->db, pWhere, 0);
      x.pParse = pParse;
      x.iTable = iCursor;


      x.pEList = pSubq->pEList;
      pNew = substExpr(&x, pNew);
      pSubq->pWhere = sqlite3ExprAnd(pParse->db, pSubq->pWhere, pNew);
      pSubq = pSubq->pPrior;
    }
  }
  return nChng;







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**
** All references to columns in table iTable are to be replaced by corresponding
** expressions in pEList.
*/
typedef struct SubstContext {
  Parse *pParse;            /* The parsing context */
  int iTable;               /* Replace references to this table */
  int iNewTable;            /* New table number */
  int isLeftJoin;           /* Add TK_IF_NULL_ROW opcodes on each replacement */
  ExprList *pEList;         /* Replacement expressions */
} SubstContext;

/* Forward Declarations */
static void substExprList(SubstContext*, ExprList*);
static void substSelect(SubstContext*, Select*, int);

................................................................................
** of the subquery rather the result set of the subquery.
*/
static Expr *substExpr(
  SubstContext *pSubst,  /* Description of the substitution */
  Expr *pExpr            /* Expr in which substitution occurs */
){
  if( pExpr==0 ) return 0;
  if( ExprHasProperty(pExpr, EP_FromJoin) && pExpr->iRightJoinTable==pSubst->iTable ){
    pExpr->iRightJoinTable = pSubst->iNewTable;
  }
  if( pExpr->op==TK_COLUMN && pExpr->iTable==pSubst->iTable ){
    if( pExpr->iColumn<0 ){
      pExpr->op = TK_NULL;
    }else{
      Expr *pNew;
      Expr *pCopy = pSubst->pEList->a[pExpr->iColumn].pExpr;
      Expr ifNullRow;
      assert( pSubst->pEList!=0 && pExpr->iColumn<pSubst->pEList->nExpr );
      assert( pExpr->pLeft==0 && pExpr->pRight==0 );
      if( sqlite3ExprIsVector(pCopy) ){
        sqlite3VectorErrorMsg(pSubst->pParse, pCopy);
      }else{
        sqlite3 *db = pSubst->pParse->db;
        if( pSubst->isLeftJoin && pCopy->op!=TK_COLUMN ){
          memset(&ifNullRow, 0, sizeof(ifNullRow));
          ifNullRow.op = TK_IF_NULL_ROW;
          ifNullRow.pLeft = pCopy;
          ifNullRow.iTable = pSubst->iNewTable;
          pCopy = &ifNullRow;
        }
        pNew = sqlite3ExprDup(db, pCopy, 0);
        if( pNew && (pExpr->flags & EP_FromJoin) ){
          pNew->iRightJoinTable = pExpr->iRightJoinTable;
          pNew->flags |= EP_FromJoin;
        }
        sqlite3ExprDelete(db, pExpr);
        pExpr = pNew;
................................................................................
**   (1)  The subquery and the outer query do not both use aggregates.
**
**   (2)  The subquery is not an aggregate or (2a) the outer query is not a join
**        and (2b) the outer query does not use subqueries other than the one
**        FROM-clause subquery that is a candidate for flattening.  (2b is
**        due to ticket [2f7170d73bf9abf80] from 2015-02-09.)
**
**   (3)  The subquery is not the right operand of a LEFT JOIN
**        or the subquery is not itself a join.
**
**   (4)  The subquery is not DISTINCT.
**
**  (**)  At one point restrictions (4) and (5) defined a subset of DISTINCT
**        sub-queries that were excluded from this optimization. Restriction 
**        (4) has since been expanded to exclude all DISTINCT subqueries.
**
**   (6)  The subquery does not use aggregates or the outer query is not
**        DISTINCT.
**
**   (7)  The subquery has a FROM clause.  TODO:  For subqueries without
**        A FROM clause, consider adding a FROM clause with the special
**        table sqlite_once that consists of a single row containing a
**        single NULL.
**
**   (8)  The subquery does not use LIMIT or the outer query is not a join.
**
**   (9)  The subquery does not use LIMIT or the outer query does not use
**        aggregates.
................................................................................
  Select *pParent;    /* Current UNION ALL term of the other query */
  Select *pSub;       /* The inner query or "subquery" */
  Select *pSub1;      /* Pointer to the rightmost select in sub-query */
  SrcList *pSrc;      /* The FROM clause of the outer query */
  SrcList *pSubSrc;   /* The FROM clause of the subquery */
  ExprList *pList;    /* The result set of the outer query */
  int iParent;        /* VDBE cursor number of the pSub result set temp table */
  int iNewParent = -1;/* Replacement table for iParent */
  int isLeftJoin = 0; /* True if pSub is the right side of a LEFT JOIN */    
  int i;              /* Loop counter */
  Expr *pWhere;                    /* The WHERE clause */
  struct SrcList_item *pSubitem;   /* The subquery */
  sqlite3 *db = pParse->db;

  /* Check to see if flattening is permitted.  Return 0 if not.
  */
................................................................................
    if( (p->pWhere && ExprHasProperty(p->pWhere,EP_Subquery))
     || (sqlite3ExprListFlags(p->pEList) & EP_Subquery)!=0
     || (sqlite3ExprListFlags(p->pOrderBy) & EP_Subquery)!=0
    ){
      return 0;                                          /* Restriction (2b)  */
    }
  }

  pSubSrc = pSub->pSrc;
  assert( pSubSrc );
  /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
  ** not arbitrary expressions, we allowed some combining of LIMIT and OFFSET
  ** because they could be computed at compile-time.  But when LIMIT and OFFSET
  ** became arbitrary expressions, we were forced to add restrictions (13)
  ** and (14). */
................................................................................
  if( pSub->selFlags & (SF_Recursive|SF_MinMaxAgg) ){
    return 0; /* Restrictions (22) and (24) */
  }
  if( (p->selFlags & SF_Recursive) && pSub->pPrior ){
    return 0; /* Restriction (23) */
  }

  /*
  ** If the subquery is the right operand of a LEFT JOIN, then the
  ** subquery may not be a join itself.  Example of why this is not allowed:

  **
  **         t1 LEFT OUTER JOIN (t2 JOIN t3)
  **
  ** If we flatten the above, we would get
  **
  **         (t1 LEFT OUTER JOIN t2) JOIN t3
  **
  ** which is not at all the same thing.
  **
  ** See also tickets #306, #350, and #3300.

















  */
  if( (pSubitem->fg.jointype & JT_OUTER)!=0 ){
    isLeftJoin = 1;
    if( pSubSrc->nSrc>1 ){
      return 0; /* Restriction (3) */
    }
  }

  /* Restriction 17: If the sub-query is a compound SELECT, then it must
  ** use only the UNION ALL operator. And none of the simple select queries
  ** that make up the compound SELECT are allowed to be aggregate or distinct
  ** queries.
  */
................................................................................
    /* Transfer the FROM clause terms from the subquery into the
    ** outer query.
    */
    for(i=0; i<nSubSrc; i++){
      sqlite3IdListDelete(db, pSrc->a[i+iFrom].pUsing);
      assert( pSrc->a[i+iFrom].fg.isTabFunc==0 );
      pSrc->a[i+iFrom] = pSubSrc->a[i];
      iNewParent = pSubSrc->a[i].iCursor;
      memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
    }
    pSrc->a[iFrom].fg.jointype = jointype;
  
    /* Now begin substituting subquery result set expressions for 
    ** references to the iParent in the outer query.
    ** 
................................................................................
      }
      assert( pParent->pOrderBy==0 );
      assert( pSub->pPrior==0 );
      pParent->pOrderBy = pOrderBy;
      pSub->pOrderBy = 0;
    }
    pWhere = sqlite3ExprDup(db, pSub->pWhere, 0);
    if( isLeftJoin ){
      setJoinExpr(pWhere, iNewParent);
    }
    if( subqueryIsAgg ){
      assert( pParent->pHaving==0 );
      pParent->pHaving = pParent->pWhere;
      pParent->pWhere = pWhere;
      pParent->pHaving = sqlite3ExprAnd(db, 
          sqlite3ExprDup(db, pSub->pHaving, 0), pParent->pHaving
      );
................................................................................
    }else{
      pParent->pWhere = sqlite3ExprAnd(db, pWhere, pParent->pWhere);
    }
    if( db->mallocFailed==0 ){
      SubstContext x;
      x.pParse = pParse;
      x.iTable = iParent;
      x.iNewTable = iNewParent;
      x.isLeftJoin = isLeftJoin;
      x.pEList = pSub->pEList;
      substSelect(&x, pParent, 0);
    }
  
    /* The flattened query is distinct if either the inner or the
    ** outer query is distinct. 
    */
................................................................................
  if( sqlite3ExprIsTableConstant(pWhere, iCursor) ){
    nChng++;
    while( pSubq ){
      SubstContext x;
      pNew = sqlite3ExprDup(pParse->db, pWhere, 0);
      x.pParse = pParse;
      x.iTable = iCursor;
      x.iNewTable = iCursor;
      x.isLeftJoin = 0;
      x.pEList = pSubq->pEList;
      pNew = substExpr(&x, pNew);
      pSubq->pWhere = sqlite3ExprAnd(pParse->db, pSubq->pWhere, pNew);
      pSubq = pSubq->pPrior;
    }
  }
  return nChng;

Changes to src/treeview.c.

465
466
467
468
469
470
471





472
473
474
475
476
477
478
      sqlite3TreeViewBareExprList(pView, pExpr->x.pList, "VECTOR");
      break;
    }
    case TK_SELECT_COLUMN: {
      sqlite3TreeViewLine(pView, "SELECT-COLUMN %d", pExpr->iColumn);
      sqlite3TreeViewSelect(pView, pExpr->pLeft->x.pSelect, 0);
      break;





    }
    default: {
      sqlite3TreeViewLine(pView, "op=%d", pExpr->op);
      break;
    }
  }
  if( zBinOp ){







>
>
>
>
>







465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
      sqlite3TreeViewBareExprList(pView, pExpr->x.pList, "VECTOR");
      break;
    }
    case TK_SELECT_COLUMN: {
      sqlite3TreeViewLine(pView, "SELECT-COLUMN %d", pExpr->iColumn);
      sqlite3TreeViewSelect(pView, pExpr->pLeft->x.pSelect, 0);
      break;
    }
    case TK_IF_NULL_ROW: {
      sqlite3TreeViewLine(pView, "IF-NULL-ROW %d", pExpr->iTable);
      sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
      break;
    }
    default: {
      sqlite3TreeViewLine(pView, "op=%d", pExpr->op);
      break;
    }
  }
  if( zBinOp ){

Changes to src/vdbe.c.

2426
2427
2428
2429
2430
2431
2432

















2433
2434
2435
2436
2437
2438
2439
  pIn1 = &aMem[pOp->p1];
  VdbeBranchTaken( (pIn1->flags & MEM_Null)==0, 2);
  if( (pIn1->flags & MEM_Null)==0 ){
    goto jump_to_p2;
  }
  break;
}


















/* Opcode: Column P1 P2 P3 P4 P5
** Synopsis: r[P3]=PX
**
** Interpret the data that cursor P1 points to as a structure built using
** the MakeRecord instruction.  (See the MakeRecord opcode for additional
** information about the format of the data.)  Extract the P2-th column







>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>







2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
  pIn1 = &aMem[pOp->p1];
  VdbeBranchTaken( (pIn1->flags & MEM_Null)==0, 2);
  if( (pIn1->flags & MEM_Null)==0 ){
    goto jump_to_p2;
  }
  break;
}

/* Opcode: IfNullRow P1 P2 P3 * *
** Synopsis: if P1.nullRow then r[P3]=NULL, goto P2
**
** Check the cursor P1 to see if it is currently pointing at a NULL row.
** If it is, then set register P3 to NULL and jump immediately to P2.
** If P1 is not on a NULL row, then fall through without making any
** changes.
*/
case OP_IfNullRow: {         /* jump */
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  if( p->apCsr[pOp->p1]->nullRow ){
    sqlite3VdbeMemSetNull(aMem + pOp->p3);
    goto jump_to_p2;
  }
  break;
}

/* Opcode: Column P1 P2 P3 P4 P5
** Synopsis: r[P3]=PX
**
** Interpret the data that cursor P1 points to as a structure built using
** the MakeRecord instruction.  (See the MakeRecord opcode for additional
** information about the format of the data.)  Extract the P2-th column

Changes to src/where.c.

5005
5006
5007
5008
5009
5010
5011


5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
            pOp->p1 = pLevel->iIdxCur;
          }
          assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 || x>=0 
              || pWInfo->eOnePass );
        }else if( pOp->opcode==OP_Rowid ){
          pOp->p1 = pLevel->iIdxCur;
          pOp->opcode = OP_IdxRowid;


        }
      }
    }
  }

  /* Final cleanup
  */
  pParse->nQueryLoop = pWInfo->savedNQueryLoop;
  whereInfoFree(db, pWInfo);
  return;
}







>
>











5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
            pOp->p1 = pLevel->iIdxCur;
          }
          assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 || x>=0 
              || pWInfo->eOnePass );
        }else if( pOp->opcode==OP_Rowid ){
          pOp->p1 = pLevel->iIdxCur;
          pOp->opcode = OP_IdxRowid;
        }else if( pOp->opcode==OP_IfNullRow ){
          pOp->p1 = pLevel->iIdxCur;
        }
      }
    }
  }

  /* Final cleanup
  */
  pParse->nQueryLoop = pWInfo->savedNQueryLoop;
  whereInfoFree(db, pWInfo);
  return;
}

Changes to tool/addopcodes.tcl.

35
36
37
38
39
40
41

42
43
44
45
46
47
48
  AGG_FUNCTION
  AGG_COLUMN
  UMINUS
  UPLUS
  REGISTER
  VECTOR
  SELECT_COLUMN

  ASTERISK
  SPAN
  SPACE
  ILLEGAL
}
if {[lrange $extras end-1 end]!="SPACE ILLEGAL"} {
  error "SPACE and ILLEGAL must be the last two token codes and they\







>







35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
  AGG_FUNCTION
  AGG_COLUMN
  UMINUS
  UPLUS
  REGISTER
  VECTOR
  SELECT_COLUMN
  IF_NULL_ROW
  ASTERISK
  SPAN
  SPACE
  ILLEGAL
}
if {[lrange $extras end-1 end]!="SPACE ILLEGAL"} {
  error "SPACE and ILLEGAL must be the last two token codes and they\