Index: src/expr.c ================================================================== --- src/expr.c +++ src/expr.c @@ -4905,10 +4905,80 @@ return sqlite3ExprCompare(0, sqlite3ExprSkipCollate(pA), sqlite3ExprSkipCollate(pB), iTab); } + +/* +** Return non-zero if Expr p can only be true if pNN is not NULL. +*/ +static int exprImpliesNotNull( + Parse *pParse, /* Parsing context */ + Expr *p, /* The expression to be checked */ + Expr *pNN, /* The expression that is NOT NULL */ + int iTab, /* Table being evaluated */ + int seenNot /* True if p is an operand of NOT */ +){ + assert( p ); + assert( pNN ); + if( sqlite3ExprCompare(pParse, p, pNN, iTab)==0 ) return 1; + switch( p->op ){ + case TK_IN: { + if( seenNot && ExprHasProperty(p, EP_xIsSelect) ) return 0; + assert( ExprHasProperty(p,EP_xIsSelect) + || (p->x.pList!=0 && p->x.pList->nExpr>0) ); + return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot); + } + case TK_BETWEEN: { + ExprList *pList = p->x.pList; + assert( pList!=0 ); + assert( pList->nExpr==2 ); + if( seenNot ) return 0; + if( exprImpliesNotNull(pParse, pList->a[0].pExpr, pNN, iTab, seenNot) + || exprImpliesNotNull(pParse, pList->a[1].pExpr, pNN, iTab, seenNot) + ){ + return 1; + } + return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot); + } + case TK_EQ: + case TK_NE: + case TK_LT: + case TK_LE: + case TK_GT: + case TK_GE: + case TK_PLUS: + case TK_MINUS: + case TK_STAR: + case TK_REM: + case TK_BITAND: + case TK_BITOR: + case TK_SLASH: + case TK_LSHIFT: + case TK_RSHIFT: + case TK_CONCAT: { + if( exprImpliesNotNull(pParse, p->pRight, pNN, iTab, seenNot) ) return 1; + /* Fall thru into the next case */ + } + case TK_SPAN: + case TK_COLLATE: + case TK_BITNOT: + case TK_UPLUS: + case TK_UMINUS: { + return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot); + } + case TK_TRUTH: { + if( seenNot ) return 0; + if( p->op2!=TK_IS ) return 0; + return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot); + } + case TK_NOT: { + return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1); + } + } + return 0; +} /* ** Return true if we can prove the pE2 will always be true if pE1 is ** true. Return false if we cannot complete the proof or if pE2 might ** be false. Examples: @@ -4942,19 +5012,13 @@ || sqlite3ExprImpliesExpr(pParse, pE1, pE2->pRight, iTab) ) ){ return 1; } if( pE2->op==TK_NOTNULL - && pE1->op!=TK_ISNULL - && pE1->op!=TK_IS - && pE1->op!=TK_ISNOT - && pE1->op!=TK_OR - && pE1->op!=TK_CASE + && exprImpliesNotNull(pParse, pE1, pE2->pLeft, iTab, 0) ){ - Expr *pX = sqlite3ExprSkipCollate(pE1->pLeft); - testcase( pX!=pE1->pLeft ); - if( sqlite3ExprCompare(pParse, pX, pE2->pLeft, iTab)==0 ) return 1; + return 1; } return 0; } /*