fixes precedence of NOT LIKE

Signed-off-by: Andres Taylor <[email protected]>

go/test/endtoend/vtgate/vitess_tester/expressions/expressions.test

@@ -0,0 +1,31 @@
+# This file contains queries that test expressions in Vitess.
+# We've found a number of bugs around precedences that we want to test.
+
+CREATE TABLE t0
+(
+    c1 BIT,
+    INDEX idx_c1 (c1)
+);
+
+INSERT INTO t0(c1)
+VALUES ('');
+
+
+SELECT *
+FROM t0;
+
+SELECT ((t0.c1 = 'a'))
+FROM t0;
+
+SELECT *
+FROM t0
+WHERE ((t0.c1 = 'a'));
+
+
+SELECT (1 LIKE ('a' IS NULL));
+SELECT (NOT (1 LIKE ('a' IS NULL)));
+
+SELECT (~ (1 || 0)) IS NULL;
+
+SELECT 1
+WHERE (~ (1 || 0)) IS NULL;

go/vt/sqlparser/analyzer.go

@@ -137,7 +137,7 @@ func ASTToStatementType(stmt Statement) StatementType {
 // CanNormalize takes Statement and returns if the statement can be normalized.
 func CanNormalize(stmt Statement) bool {
 	switch stmt.(type) {
-	case *Select, *Union, *Insert, *Update, *Delete, *Set, *CallProc, *Stream: // TODO: we could merge this logic into ASTrewriter
+	case *Select, *Union, *Insert, *Update, *Delete, *Set, *CallProc, *Stream, *VExplainStmt: // TODO: we could merge this logic into ASTrewriter
 		return true
 	}
 	return false

go/vt/sqlparser/precedence.go

@@ -57,10 +57,7 @@ func precedenceFor(in Expr) Precendence {
 	case *BetweenExpr:
 		return P12
 	case *ComparisonExpr:
-		switch node.Operator {
-		case EqualOp, NotEqualOp, GreaterThanOp, GreaterEqualOp, LessThanOp, LessEqualOp, LikeOp, InOp, RegexpOp, NullSafeEqualOp:
-			return P11
-		}
+		return P11
 	case *IsExpr:
 		return P11
 	case *BinaryExpr:

go/vt/sqlparser/precedence_test.go

@@ -159,6 +159,8 @@ func TestParens(t *testing.T) {
 		{in: "10 - (2 - 1)", expected: "10 - (2 - 1)"},
 		{in: "0 <=> (1 and 0)", expected: "0 <=> (1 and 0)"},
 		{in: "(~ (1||0)) IS NULL", expected: "~(1 or 0) is null"},
+		{in: "1 not like ('a' is null)", expected: "1 not like ('a' is null)"},
+		{in: ":vtg1 not like (:vtg2 is null)", expected: ":vtg1 not like (:vtg2 is null)"},
 	}
 
 	parser := NewTestParser()