Fix alias-for-target-table-of-UPDATE-or-DELETE patch so that alias can

tglsfdc · tglsfdc · commit 2647ad6583c7 · 2006-01-22T20:03:16.000Z
be any ColId other than 'SET', rather than only IDENT as originally.
Per discussion.
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.523 2006/01/22 05:20:33 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.524 2006/01/22 20:03:16 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -429,6 +429,7 @@ static void doNegateFloat(Value *v);
 %token <ival>	ICONST PARAM
 
 /* precedence: lowest to highest */
+%nonassoc	SET				/* see relation_expr_opt_alias */
 %left		UNION EXCEPT
 %left		INTERSECT
 %left		OR
@@ -5880,11 +5881,27 @@ relation_expr:
 		;
 
 
-relation_expr_opt_alias: relation_expr
+/*
+ * Given "UPDATE foo set set ...", we have to decide without looking any
+ * further ahead whether the first "set" is an alias or the UPDATE's SET
+ * keyword.  Since "set" is allowed as a column name both interpretations
+ * are feasible.  We resolve the shift/reduce conflict by giving the first
+ * relation_expr_opt_alias production a higher precedence than the SET token
+ * has, causing the parser to prefer to reduce, in effect assuming that the
+ * SET is not an alias.
+ */
+relation_expr_opt_alias: relation_expr					%prec UMINUS
 				{
 					$$ = $1;
 				}
-			| relation_expr opt_as IDENT
+			| relation_expr ColId
+				{
+					Alias *alias = makeNode(Alias);
+					alias->aliasname = $2;
+					$1->alias = alias;
+					$$ = $1;
+				}
+			| relation_expr AS ColId
 				{
 					Alias *alias = makeNode(Alias);
 					alias->aliasname = $3;
@@ -6827,7 +6844,7 @@ a_expr:		c_expr									{ $$ = $1; }
 						$$ = (Node *) makeSimpleA_Expr(AEXPR_IN, "<>", $1, $4);
 					}
 				}
-			| a_expr subquery_Op sub_type select_with_parens %prec Op
+			| a_expr subquery_Op sub_type select_with_parens	%prec Op
 				{
 					SubLink *n = makeNode(SubLink);
 					n->subLinkType = $3;
@@ -6836,14 +6853,14 @@ a_expr:		c_expr									{ $$ = $1; }
 					n->subselect = $4;
 					$$ = (Node *)n;
 				}
-			| a_expr subquery_Op sub_type '(' a_expr ')' %prec Op
+			| a_expr subquery_Op sub_type '(' a_expr ')'		%prec Op
 				{
 					if ($3 == ANY_SUBLINK)
 						$$ = (Node *) makeA_Expr(AEXPR_OP_ANY, $2, $1, $5);
 					else
 						$$ = (Node *) makeA_Expr(AEXPR_OP_ALL, $2, $1, $5);
 				}
-			| UNIQUE select_with_parens %prec Op
+			| UNIQUE select_with_parens
 				{
 					/* Not sure how to get rid of the parentheses
 					 * but there are lots of shift/reduce errors without them.
@@ -6901,7 +6918,7 @@ b_expr:		c_expr
 				{ $$ = (Node *) makeA_Expr(AEXPR_OP, $1, NULL, $2); }
 			| b_expr qual_Op					%prec POSTFIXOP
 				{ $$ = (Node *) makeA_Expr(AEXPR_OP, $2, $1, NULL); }
-			| b_expr IS DISTINCT FROM b_expr	%prec IS
+			| b_expr IS DISTINCT FROM b_expr		%prec IS
 				{
 					$$ = (Node *) makeSimpleA_Expr(AEXPR_DISTINCT, "=", $1, $5);
 				}
@@ -6910,7 +6927,7 @@ b_expr:		c_expr
 					$$ = (Node *) makeA_Expr(AEXPR_NOT, NIL,
 						NULL, (Node *) makeSimpleA_Expr(AEXPR_DISTINCT, "=", $1, $6));
 				}
-			| b_expr IS OF '(' type_list ')'	%prec IS
+			| b_expr IS OF '(' type_list ')'		%prec IS
 				{
 					$$ = (Node *) makeSimpleA_Expr(AEXPR_OF, "=", $1, (Node *) $5);
 				}

Original file line number	Diff line number	Diff line change
`@@ -11,7 +11,7 @@`
`11`	`11`	`*`
`12`	`12`	`*`
`13`	`13`	`* IDENTIFICATION`
`14`		`- * $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.523 2006/01/22 05:20:33 neilc Exp $`
	`14`	`+ * $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.524 2006/01/22 20:03:16 tgl Exp $`
`15`	`15`	`*`
`16`	`16`	`* HISTORY`
`17`	`17`	`* AUTHOR DATE MAJOR EVENT`
`@@ -429,6 +429,7 @@ static void doNegateFloat(Value *v);`
`429`	`429`	`%token <ival> ICONST PARAM`
`430`	`430`
`431`	`431`	`/* precedence: lowest to highest */`
	`432`	`+%nonassoc SET /* see relation_expr_opt_alias */`
`432`	`433`	`%left UNION EXCEPT`
`433`	`434`	`%left INTERSECT`
`434`	`435`	`%left OR`
`@@ -5880,11 +5881,27 @@ relation_expr:`
`5880`	`5881`	`;`
`5881`	`5882`
`5882`	`5883`
`5883`		`-relation_expr_opt_alias: relation_expr`
	`5884`	`+/*`
	`5885`	`+ * Given "UPDATE foo set set ...", we have to decide without looking any`
	`5886`	`+ * further ahead whether the first "set" is an alias or the UPDATE's SET`
	`5887`	`+ * keyword. Since "set" is allowed as a column name both interpretations`
	`5888`	`+ * are feasible. We resolve the shift/reduce conflict by giving the first`
	`5889`	`+ * relation_expr_opt_alias production a higher precedence than the SET token`
	`5890`	`+ * has, causing the parser to prefer to reduce, in effect assuming that the`
	`5891`	`+ * SET is not an alias.`
	`5892`	`+ */`
	`5893`	`+relation_expr_opt_alias: relation_expr %prec UMINUS`
`5884`	`5894`	`{`
`5885`	`5895`	`$$ = $1;`
`5886`	`5896`	`}`
`5887`		`- \| relation_expr opt_as IDENT`
	`5897`	`+ \| relation_expr ColId`
	`5898`	`+ {`
	`5899`	`+ Alias *alias = makeNode(Alias);`
	`5900`	`+ alias->aliasname = $2;`
	`5901`	`+ $1->alias = alias;`
	`5902`	`+ $$ = $1;`
	`5903`	`+ }`
	`5904`	`+ \| relation_expr AS ColId`
`5888`	`5905`	`{`
`5889`	`5906`	`Alias *alias = makeNode(Alias);`
`5890`	`5907`	`alias->aliasname = $3;`
`@@ -6827,7 +6844,7 @@ a_expr: c_expr { $$ = $1; }`
`6827`	`6844`	`$$ = (Node *) makeSimpleA_Expr(AEXPR_IN, "<>", $1, $4);`
`6828`	`6845`	`}`
`6829`	`6846`	`}`
`6830`		`- \| a_expr subquery_Op sub_type select_with_parens %prec Op`
	`6847`	`+ \| a_expr subquery_Op sub_type select_with_parens %prec Op`
`6831`	`6848`	`{`
`6832`	`6849`	`SubLink *n = makeNode(SubLink);`
`6833`	`6850`	`n->subLinkType = $3;`
`@@ -6836,14 +6853,14 @@ a_expr: c_expr { $$ = $1; }`
`6836`	`6853`	`n->subselect = $4;`
`6837`	`6854`	`$$ = (Node *)n;`
`6838`	`6855`	`}`
`6839`		`- \| a_expr subquery_Op sub_type '(' a_expr ')' %prec Op`
	`6856`	`+ \| a_expr subquery_Op sub_type '(' a_expr ')' %prec Op`
`6840`	`6857`	`{`
`6841`	`6858`	`if ($3 == ANY_SUBLINK)`
`6842`	`6859`	`$$ = (Node *) makeA_Expr(AEXPR_OP_ANY, $2, $1, $5);`
`6843`	`6860`	`else`
`6844`	`6861`	`$$ = (Node *) makeA_Expr(AEXPR_OP_ALL, $2, $1, $5);`
`6845`	`6862`	`}`
`6846`		`- \| UNIQUE select_with_parens %prec Op`
	`6863`	`+ \| UNIQUE select_with_parens`
`6847`	`6864`	`{`
`6848`	`6865`	`/* Not sure how to get rid of the parentheses`
`6849`	`6866`	`* but there are lots of shift/reduce errors without them.`
`@@ -6901,7 +6918,7 @@ b_expr: c_expr`
`6901`	`6918`	`{ $$ = (Node *) makeA_Expr(AEXPR_OP, $1, NULL, $2); }`
`6902`	`6919`	`\| b_expr qual_Op %prec POSTFIXOP`
`6903`	`6920`	`{ $$ = (Node *) makeA_Expr(AEXPR_OP, $2, $1, NULL); }`
`6904`		`- \| b_expr IS DISTINCT FROM b_expr %prec IS`
	`6921`	`+ \| b_expr IS DISTINCT FROM b_expr %prec IS`
`6905`	`6922`	`{`
`6906`	`6923`	`$$ = (Node *) makeSimpleA_Expr(AEXPR_DISTINCT, "=", $1, $5);`
`6907`	`6924`	`}`
`@@ -6910,7 +6927,7 @@ b_expr: c_expr`
`6910`	`6927`	`$$ = (Node *) makeA_Expr(AEXPR_NOT, NIL,`
`6911`	`6928`	`NULL, (Node *) makeSimpleA_Expr(AEXPR_DISTINCT, "=", $1, $6));`
`6912`	`6929`	`}`
`6913`		`- \| b_expr IS OF '(' type_list ')' %prec IS`
	`6930`	`+ \| b_expr IS OF '(' type_list ')' %prec IS`
`6914`	`6931`	`{`
`6915`	`6932`	`$$ = (Node ) makeSimpleA_Expr(AEXPR_OF, "=", $1, (Node ) $5);`
`6916`	`6933`	`}`