planner: check whether values are const in constant propagation (#45119)

close #45086
pingcap · Jul 3, 2023 · 6f79794 · 6f79794
1 parent e7e8fc1
commit 6f79794
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Showing 2 changed files with 14 additions and 2 deletions.
diff --git a/expression/constant_propagation.go b/expression/constant_propagation.go
@@ -56,7 +56,7 @@ func (s *basePropConstSolver) insertCol(col *Column) {
 // tryToUpdateEQList tries to update the eqList. When the eqList has store this column with a different constant, like
 // a = 1 and a = 2, we set the second return value to false.
 func (s *basePropConstSolver) tryToUpdateEQList(col *Column, con *Constant) (bool, bool) {
-	if con.Value.IsNull() {
+	if con.ConstItem(s.ctx.GetSessionVars().StmtCtx) && con.Value.IsNull() {
 		return false, true
 	}
 	id := s.getColID(col)

diff --git a/planner/core/plan_cache_test.go b/planner/core/plan_cache_test.go
@@ -52,6 +52,18 @@ func TestInitLRUWithSystemVar(t *testing.T) {
 	require.NotNil(t, lru)
 }
 
+func TestIssue45086(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec(`use test`)
+
+	tk.MustExec(`CREATE TABLE t (a int(11) DEFAULT NULL, b date DEFAULT NULL)`)
+	tk.MustExec(`INSERT INTO t VALUES (1, current_date())`)
+
+	tk.MustExec(`PREPARE stmt FROM 'SELECT * FROM t WHERE b=current_date()'`)
+	require.Equal(t, len(tk.MustQuery(`EXECUTE stmt`).Rows()), 1)
+}
+
 func TestIssue43311(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)
@@ -955,7 +967,7 @@ func TestIssue43852(t *testing.T) {
 	tk.MustExec(`set tidb_enable_non_prepared_plan_cache=1`)
 	tk.MustQuery(`select * from t6 where a in (2015, '8')`).Check(testkit.Rows())
 	tk.MustQuery(`select * from t6 where a in (2009, '2023-01-21')`).Check(testkit.Rows(`2023-01-21 2023-01-05`))
-	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0"))
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
 }
 
 func TestNonPreparedPlanTypeRandomly(t *testing.T) {