Support PostgreSQL double qouted columns

sqlparser/parse_test.go

@@ -211,6 +211,20 @@ var (
 		output: "select /* string table alias */ 1 from t as 't1'",
 		// mysql allow to use single quote for column/table aliases
 		dialect: mysql.NewMySQLDialect(),
+	}, {
+		input: `select * from mytable where "AGE" = 1 and "TEST" = 'test'`,
+		// postgres allow to use double quote string for columns
+		dialect: postgresql.NewPostgreSQLDialect(),
+	}, {
+		input:  `select * from mytable where "test" = "test"`,
+		output: `select * from mytable where 'test' = 'test'`,
+	}, {
+		input:  `select * from mytable where "test" = 1 and 'value' = 'value'`,
+		output: `select * from mytable where 'test' = 1 and 'value' = 'value'`,
+	}, {
+		input:   `SELECT "id", "landline_number" AS "landlineNumber", "removal" FROM "users" AS "User" where "User"."is_active"`,
+		output:  `select "id", "landline_number" as "landlineNumber", "removal" from "users" as "User" where "User"."is_active"`,
+		dialect: postgresql.NewPostgreSQLDialect(),
 	}, {
 		input:  "select /* string table alias without as */ 1 from t 't1'",
 		output: "select /* string table alias without as */ 1 from t as 't1'",
@@ -1322,11 +1336,17 @@ var (
 )
 
 func TestValid(t *testing.T) {
+	var testDialect dialect.Dialect
 	for i, tcase := range validSQL {
 		if tcase.output == "" {
 			tcase.output = tcase.input
 		}
-		tree, err := New(ModeStrict).Parse(tcase.input)
+
+		testDialect = tcase.dialect
+		if tcase.dialect == nil {
+			testDialect = mysql.NewMySQLDialect()
+		}
+		tree, err := ParseWithDialect(testDialect, tcase.input)
 		if err != nil {
 			t.Errorf("Parse(%q) err: %v, want nil", tcase.input, err)
 			continue