From f81851f83cb201d4b25bdfd66983e571f075ccc3 Mon Sep 17 00:00:00 2001
From: HuaiyuXu <391585975@qq.com>
Date: Sun, 30 Sep 2018 16:15:11 +0800
Subject: [PATCH] ast, plan: return error when the arg of VALUES() function is
 not a column (#7817)

---
 ast/expressions.go                   | 4 +++-
 planner/core/logical_plan_builder.go | 4 ++++
 planner/core/logical_plan_test.go    | 1 +
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/ast/expressions.go b/ast/expressions.go
index 440a89e06fdd6..e359b121c7444 100644
--- a/ast/expressions.go
+++ b/ast/expressions.go
@@ -927,7 +927,9 @@ func (n *ValuesExpr) Accept(v Visitor) (Node, bool) {
 	if !ok {
 		return n, false
 	}
-	n.Column = node.(*ColumnNameExpr)
+	// `node` may be *ast.ValueExpr, to avoid panic, we write `ok` but do not use
+	// it.
+	n.Column, ok = node.(*ColumnNameExpr)
 	return v.Leave(n)
 }
 
diff --git a/planner/core/logical_plan_builder.go b/planner/core/logical_plan_builder.go
index 35653f2db8a8f..9ebf16ede572e 100644
--- a/planner/core/logical_plan_builder.go
+++ b/planner/core/logical_plan_builder.go
@@ -1164,6 +1164,10 @@ func (g *gbyResolver) Leave(inNode ast.Node) (ast.Node, bool) {
 			return inNode, false
 		}
 		return ret, true
+	case *ast.ValuesExpr:
+		if v.Column == nil {
+			g.err = ErrUnknownColumn.GenWithStackByArgs("", "VALUES() function")
+		}
 	}
 	return inNode, true
 }
diff --git a/planner/core/logical_plan_test.go b/planner/core/logical_plan_test.go
index 569f97e45f199..7ebf51cc02c48 100644
--- a/planner/core/logical_plan_test.go
+++ b/planner/core/logical_plan_test.go
@@ -1985,6 +1985,7 @@ func (s *testPlanSuite) TestNameResolver(c *C) {
 		{"select a from t group by t11.c1", "[planner:1054]Unknown column 't11.c1' in 'group statement'"},
 		{"delete a from (select * from t ) as a, t", "[planner:1288]The target table a of the DELETE is not updatable"},
 		{"delete b from (select * from t ) as a, t", "[planner:1109]Unknown table 'b' in MULTI DELETE"},
+		{"select '' as fakeCol from t group by values(fakeCol)", "[planner:1054]Unknown column '' in 'VALUES() function'"},
 		{"update t, (select * from t) as b set b.a = t.a", "[planner:1288]The target table b of the UPDATE is not updatable"},
 	}