planner: a quick fix to solve the column alias in ORDER BY's subquery (…

…#45003) (#45068)

close #42732

planner/core/issuetest/BUILD.bazel

@@ -2,6 +2,10 @@ load("@io_bazel_rules_go//go:def.bzl", "go_test")
 
 go_test(
     name = "issuetest_test",
+    timeout = "short",
     srcs = ["planner_issue_test.go"],
+    flaky = True,
+    race = "on",
+    shard_count = 5,
     deps = ["//testkit"],
 )

planner/core/issuetest/planner_issue_test.go

@@ -33,3 +33,15 @@ func TestIssue44051(t *testing.T) {
 	rs := tk.MustQuery("WITH tmp AS (SELECT t2.* FROM t2) SELECT * FROM t1 WHERE t1.id = (select id from tmp where id = 1) or t1.id = (select id from tmp where id = 2) or t1.id = (select id from tmp where id = 3)")
 	rs.Sort().Check(testkit.Rows("1 <nil> <nil> <nil>", "2 <nil> <nil> <nil>", "3 <nil> <nil> <nil>"))
 }
+
+func TestIssue42732(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+
+	tk.MustExec("use test")
+	tk.MustExec("CREATE TABLE t1 (a INT, b INT)")
+	tk.MustExec("CREATE TABLE t2 (a INT, b INT)")
+	tk.MustExec("INSERT INTO t1 VALUES (1, 1)")
+	tk.MustExec("INSERT INTO t2 VALUES (1, 1)")
+	tk.MustQuery("SELECT one.a, one.b as b2 FROM t1 one ORDER BY (SELECT two.b FROM t2 two WHERE two.a = one.b)").Check(testkit.Rows("1 1"))
+}

planner/core/logical_plan_builder.go

@@ -2432,8 +2432,9 @@ func (b *PlanBuilder) resolveHavingAndOrderBy(ctx context.Context, sel *ast.Sele
 					if colName != nil {
 						columnNameExpr := &ast.ColumnNameExpr{Name: colName}
 						for _, field := range sel.Fields.Fields {
-							if c, ok := field.Expr.(*ast.ColumnNameExpr); ok && colMatch(c.Name, columnNameExpr.Name) {
+							if c, ok := field.Expr.(*ast.ColumnNameExpr); ok && colMatch(c.Name, columnNameExpr.Name) && field.AsName.L == "" {
 								// deduplicate select fields: don't append it once it already has one.
+								// TODO: we add the field if it has alias, but actually they are the same column. We should not have two duplicate one.
 								columnNameExpr = nil
 								break
 							}