planner: fix wrong schema when to solve the schema name in CTE (#57253)…

… (#57333)

close #54582

planner/core/logical_plan_builder.go

@@ -7598,7 +7598,9 @@ func (b *PlanBuilder) adjustCTEPlanOutputName(p LogicalPlan, def *ast.CommonTabl
 	outPutNames := p.OutputNames()
 	for _, name := range outPutNames {
 		name.TblName = def.Name
-		name.DBName = model.NewCIStr(b.ctx.GetSessionVars().CurrentDB)
+		if name.DBName.String() == "" {
+			name.DBName = model.NewCIStr(b.ctx.GetSessionVars().CurrentDB)
+		}
 	}
 	if len(def.ColNameList) > 0 {
 		if len(def.ColNameList) != len(p.OutputNames()) {

planner/core/tests/cte/BUILD.bazel

@@ -0,0 +1,16 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_test")
+
+go_test(
+    name = "cte_test",
+    timeout = "short",
+    srcs = [
+        "cte_test.go",
+        "main_test.go",
+    ],
+    flaky = True,
+    deps = [
+        "//testkit",
+        "//testkit/testsetup",
+        "@org_uber_go_goleak//:goleak",
+    ],
+)

planner/core/tests/cte/cte_test.go

@@ -0,0 +1,54 @@
+// Copyright 2024 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cte
+
+import (
+	"testing"
+
+	"github.com/pingcap/tidb/testkit"
+)
+
+func TestCTEWithDifferentSchema(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("CREATE USER 'db_a'@'%';")
+	tk.MustExec("CREATE USER 'db_b'@'%';")
+	tk.MustExec("GRANT ALL PRIVILEGES ON `db_a`.* TO 'db_a'@'%';")
+	tk.MustExec("GRANT ALL PRIVILEGES ON `db_b`.* TO 'db_a'@'%';")
+	tk.MustExec("GRANT ALL PRIVILEGES ON `db_b`.* TO 'db_b'@'%';")
+	tk.MustExec("GRANT ALL PRIVILEGES ON `db_b`.* TO 'db_b'@'%';")
+	tk.MustExec("create database db_a;")
+	tk.MustExec("create database db_b;")
+	tk.MustExec("use db_a;")
+	tk.MustExec(`CREATE TABLE tmp_table1 (
+   id decimal(18,0) NOT NULL,
+   row_1 varchar(255) DEFAULT NULL,
+   PRIMARY KEY (id) /*T![clustered_index] CLUSTERED */
+ ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin`)
+	tk.MustExec(`create ALGORITHM=UNDEFINED DEFINER=db_a@'%' SQL SECURITY DEFINER VIEW view_test_v1 as (
+                         with rs1 as(
+                            select otn.*
+                             from tmp_table1 otn
+                          )
+                        select ojt.* from rs1 ojt
+                        )`)
+	tk.MustExec("use db_b;")
+	tk.MustQuery("explain select * from db_a.view_test_v1;").Check(testkit.Rows(
+		"CTEFullScan_11 10000.00 root CTE:rs1 AS ojt data:CTE_0",
+		"CTE_0 10000.00 root  Non-Recursive CTE",
+		"└─TableReader_9(Seed Part) 10000.00 root  data:TableFullScan_8",
+		"  └─TableFullScan_8 10000.00 cop[tikv] table:otn keep order:false, stats:pseudo"))
+}

planner/core/tests/cte/main_test.go

@@ -0,0 +1,34 @@
+// Copyright 2024 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cte
+
+import (
+	"flag"
+	"testing"
+
+	"github.com/pingcap/tidb/testkit/testsetup"
+	"go.uber.org/goleak"
+)
+
+func TestMain(m *testing.M) {
+	testsetup.SetupForCommonTest()
+	flag.Parse()
+	opts := []goleak.Option{
+		goleak.IgnoreTopFunction("github.com/golang/glog.(*loggingT).flushDaemon"),
+		goleak.IgnoreTopFunction("github.com/bazelbuild/rules_go/go/tools/bzltestutil.RegisterTimeoutHandler.func1"),
+		goleak.IgnoreTopFunction("github.com/lestrrat-go/httprc.runFetchWorker"),
+	}
+	goleak.VerifyTestMain(m, opts...)
+}