Deparser: Fix handling of constraint key named "value" in ALTER TABLE

This was being ignored in all cases, but it should only be ignored
if the Constraint object is originating in an ALTER DOMAIN statement.

pganalyze/pg_query_go#148

Author: lfittl

src/postgres_deparse.c

@@ -93,6 +93,7 @@ typedef enum DeparseNodeContext {
 	DEPARSE_NODE_CONTEXT_A_EXPR,
 	DEPARSE_NODE_CONTEXT_CREATE_TYPE,
 	DEPARSE_NODE_CONTEXT_ALTER_TYPE,
+	DEPARSE_NODE_CONTEXT_ALTER_DOMAIN,
 	DEPARSE_NODE_CONTEXT_SET_STATEMENT,
 	DEPARSE_NODE_CONTEXT_FUNC_EXPR,
 	DEPARSE_NODE_CONTEXT_SELECT_SETOP,
@@ -231,7 +232,7 @@ static void deparseJsonFuncExpr(DeparseState *state, JsonFuncExpr *json_func_exp
 static void deparseJsonQuotesClauseOpt(DeparseState *state, JsonQuotes quotes);
 static void deparseJsonOnErrorClauseOpt(DeparseState *state, JsonBehavior *behavior);
 static void deparseJsonOnEmptyClauseOpt(DeparseState *state, JsonBehavior *behavior);
-static void deparseConstraint(DeparseState *state, Constraint *constraint);
+static void deparseConstraint(DeparseState *state, Constraint *constraint, DeparseNodeContext context);
 static void deparseSchemaStmt(DeparseState *state, Node *node);
 static void deparseExecuteStmt(DeparseState *state, ExecuteStmt *execute_stmt);
 static void deparseTriggerTransition(DeparseState *state, TriggerTransition *trigger_transition);
@@ -4769,7 +4770,7 @@ static void deparseColumnDef(DeparseState *state, ColumnDef *column_def)
 
 	foreach(lc, column_def->constraints)
 	{
-		deparseConstraint(state, castNode(Constraint, lfirst(lc)));
+		deparseConstraint(state, castNode(Constraint, lfirst(lc)), DEPARSE_NODE_CONTEXT_NONE);
 		deparseAppendStringInfoChar(state, ' ');
 	}
 
@@ -5332,7 +5333,7 @@ static void deparseCreateDomainStmt(DeparseState *state, CreateDomainStmt *creat
 
 	foreach(lc, create_domain_stmt->constraints)
 	{
-		deparseConstraint(state, castNode(Constraint, lfirst(lc)));
+		deparseConstraint(state, castNode(Constraint, lfirst(lc)), DEPARSE_NODE_CONTEXT_NONE);
 		deparseAppendStringInfoChar(state, ' ');
 	}
 
@@ -5381,7 +5382,7 @@ static void deparseCreateExtensionStmt(DeparseState *state, CreateExtensionStmt
 }
 
 // "ColConstraintElem" and "ConstraintElem" in gram.y
-static void deparseConstraint(DeparseState *state, Constraint *constraint)
+static void deparseConstraint(DeparseState *state, Constraint *constraint, DeparseNodeContext context)
 {
 	ListCell *lc;
 
@@ -5487,7 +5488,7 @@ static void deparseConstraint(DeparseState *state, Constraint *constraint)
 	{
 		bool valueOnly = false;
 
-		if (list_length(constraint->keys) == 1) {
+		if (context == DEPARSE_NODE_CONTEXT_ALTER_DOMAIN && list_length(constraint->keys) == 1) {
 			Node* firstKey = constraint->keys->elements[0].ptr_value;
 			valueOnly = IsA(firstKey, String) && !strcmp("value", ((String*)firstKey)->sval);
 		}
@@ -5997,7 +5998,7 @@ static void deparseTableElement(DeparseState *state, Node *node)
 			deparseTableLikeClause(state, castNode(TableLikeClause, node));
 			break;
 		case T_Constraint:
-			deparseConstraint(state, castNode(Constraint, node));
+			deparseConstraint(state, castNode(Constraint, node), DEPARSE_NODE_CONTEXT_NONE);
 			break;
 		default:
 			Assert(false);
@@ -7286,7 +7287,7 @@ static void deparseAlterTableCmd(DeparseState *state, AlterTableCmd *alter_table
 		case AT_AddIdentity:
 		case AT_AddConstraint:
 		case AT_AlterConstraint:
-			deparseConstraint(state, castNode(Constraint, alter_table_cmd->def));
+			deparseConstraint(state, castNode(Constraint, alter_table_cmd->def), DEPARSE_NODE_CONTEXT_NONE);
 			deparseAppendStringInfoChar(state, ' ');
 			break;
 		case AT_SetIdentity:
@@ -7452,7 +7453,7 @@ static void deparseAlterDomainStmt(DeparseState *state, AlterDomainStmt *alter_d
 			break;
 		case 'C':
 			deparseAppendStringInfoString(state, "ADD ");
-			deparseConstraint(state, castNode(Constraint, alter_domain_stmt->def));
+			deparseConstraint(state, castNode(Constraint, alter_domain_stmt->def), DEPARSE_NODE_CONTEXT_ALTER_DOMAIN);
 			break;
 		case 'X':
 			deparseAppendStringInfoString(state, "DROP CONSTRAINT ");

test/deparse_tests.c

@@ -416,7 +416,8 @@ const char* tests[] = {
   "CREATE TABLE my_table (created_at timestamptz NOT NULL DEFAULT '1 hour'::interval + (current_timestamp AT TIME ZONE 'UTC'))",
   "ALTER TABLE my_table ADD COLUMN created_at timestamptz NOT NULL DEFAULT '1 hour'::interval + (current_timestamp AT TIME ZONE 'UTC')",
   "CREATE TABLE my_table (created_at int NOT NULL DEFAULT 1 + 2)",
-  "/* Comment 1 */ SELECT 1; /* Comment 2 */ SELECT 2"
+  "/* Comment 1 */ SELECT 1; /* Comment 2 */ SELECT 2",
+  "ALTER TABLE ONLY public.api_keys ADD CONSTRAINT api_keys_value_unique UNIQUE (value)"
 };
 
 size_t testsLength = __LINE__ - 4;