planner: fix nil pointer at expression.(*CorrelatedColumn).Eval (#42789…

…) (#48977)

close #42739

planner/core/logical_plan_builder.go

@@ -288,6 +288,7 @@ func (b *PlanBuilder) buildAggregation(ctx context.Context, p LogicalPlan, aggFu
 					if _, ok = b.correlatedAggMapper[aggFuncList[j]]; !ok {
 						b.correlatedAggMapper[aggFuncList[j]] = &expression.CorrelatedColumn{
 							Column: *schema4Agg.Columns[aggIndexMap[j]],
+							Data:   new(types.Datum),
 						}
 					}
 					b.correlatedAggMapper[aggFunc] = b.correlatedAggMapper[aggFuncList[j]]
@@ -309,6 +310,7 @@ func (b *PlanBuilder) buildAggregation(ctx context.Context, p LogicalPlan, aggFu
 			if _, ok := correlatedAggMap[aggFunc]; ok {
 				b.correlatedAggMapper[aggFunc] = &expression.CorrelatedColumn{
 					Column: column,
+					Data:   new(types.Datum),
 				}
 			}
 		}

planner/core/prepare_test.go

@@ -2806,3 +2806,28 @@ func TestIssue37901(t *testing.T) {
 	tk.MustExec(`execute st1 using @t`)
 	tk.MustQuery(`select count(*) from t4`).Check(testkit.Rows("2"))
 }
+
+func TestIssue42739(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+
+	tk.MustExec(`use test`)
+	tk.MustExec(`drop table if exists t0`)
+	tk.MustExec(`CREATE TABLE t0 (c1 double, c2 double);`)
+	tk.MustExec(`select
+  exists (
+    select
+          subq_2.c0 as c8
+        from
+          (select
+                ref_153.c1 as c0
+              from
+                t0 as ref_153
+              group by ref_153.c1 having 0 <> (
+                  select 1
+                    from
+                      t0 as ref_173
+                    where count(ref_153.c2) = avg(ref_153.c2)
+                    order by c1 desc limit 1)) as subq_2
+     ) as c10;`)
+}