planner: reset not null flag when Apply convert to Join (#19567)

pingcap · Aug 31, 2020 · 27ea908 · 27ea908
1 parent 1a3103a
commit 27ea908
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Showing 2 changed files with 25 additions and 2 deletions.
diff --git a/expression/integration_test.go b/expression/integration_test.go
@@ -7114,3 +7114,16 @@ func (s *testIntegrationSerialSuite) TestIssue17063(c *C) {
 	tk.MustQuery(`select collation(lag(b, 1, 'B') over w) from t window w as (order by b);`).Check(testkit.Rows("utf8mb4_general_ci", "utf8mb4_general_ci"))
 	tk.MustQuery(`select coercibility(lag(b, 1, 'B') over w) from t window w as (order by b);`).Check(testkit.Rows("2", "2"))
 }
+
+func (s *testIntegrationSuite) TestIssue19504(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t1;")
+	tk.MustExec("create table t1 (c_int int, primary key (c_int));")
+	tk.MustExec("insert into t1 values (1), (2), (3);")
+	tk.MustExec("drop table if exists t2;")
+	tk.MustExec("create table t2 (c_int int, primary key (c_int));")
+	tk.MustExec("insert into t2 values (1);")
+	tk.MustQuery("select (select count(c_int) from t2 where c_int = t1.c_int) c1, (select count(1) from t2 where c_int = t1.c_int) c2 from t1;").
+		Check(testkit.Rows("1 1", "0 0", "0 0"))
+}
diff --git a/planner/core/rule_decorrelate.go b/planner/core/rule_decorrelate.go
@@ -185,9 +185,19 @@ func (s *decorrelateSolver) optimize(ctx context.Context, p LogicalPlan) (Logica
 					outerCol.RetType = first.RetTp
 					outerColsInSchema = append(outerColsInSchema, outerCol)
 				}
-				newAggFuncs = append(newAggFuncs, agg.AggFuncs...)
-				agg.AggFuncs = newAggFuncs
 				apply.SetSchema(expression.MergeSchema(expression.NewSchema(outerColsInSchema...), innerPlan.Schema()))
+				resetNotNullFlag(apply.schema, outerPlan.Schema().Len(), apply.schema.Len())
+
+				for i, aggFunc := range agg.AggFuncs {
+					if idx := apply.schema.ColumnIndex(aggFunc.Args[0].(*expression.Column)); idx != -1 {
+						desc, err := aggregation.NewAggFuncDesc(agg.ctx, agg.AggFuncs[i].Name, []expression.Expression{apply.schema.Columns[idx]}, false)
+						if err != nil {
+							return nil, err
+						}
+						newAggFuncs = append(newAggFuncs, desc)
+					}
+				}
+				agg.AggFuncs = newAggFuncs
 				np, err := s.optimize(ctx, p)
 				if err != nil {
 					return nil, err