From 5268094afe05c7efef0d91d2deeec428cc85abe6 Mon Sep 17 00:00:00 2001
From: HuaiyuXu <391585975@qq.com>
Date: Tue, 17 Mar 2020 22:20:13 +0800
Subject: [PATCH] planner: correct the dbName for hint (#15319)

---
 planner/core/physical_plan_test.go        | 48 +++++++++++++++++++++++
 planner/core/planbuilder.go               |  2 +-
 planner/core/testdata/plan_suite_in.json  |  6 +++
 planner/core/testdata/plan_suite_out.json |  9 +++++
 4 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/planner/core/physical_plan_test.go b/planner/core/physical_plan_test.go
index 9c8fc01e00ed9..3d0488c1ac8e3 100644
--- a/planner/core/physical_plan_test.go
+++ b/planner/core/physical_plan_test.go
@@ -1277,3 +1277,51 @@ func (s *testPlanSuite) TestNominalSort(c *C) {
 		tk.MustQuery(ts).Check(testkit.Rows(output[i].Result...))
 	}
 }
+
+func (s *testPlanSuite) TestHintFromDiffDatabase(c *C) {
+	defer testleak.AfterTest(c)()
+	store, dom, err := newStoreWithBootstrap()
+	c.Assert(err, IsNil)
+	defer func() {
+		dom.Close()
+		store.Close()
+	}()
+	se, err := session.CreateSession4Test(store)
+	c.Assert(err, IsNil)
+	ctx := context.Background()
+	_, err = se.Execute(ctx, "use test")
+	c.Assert(err, IsNil)
+	_, err = se.Execute(ctx, `drop table if exists test.t1`)
+	c.Assert(err, IsNil)
+	_, err = se.Execute(ctx, `create table test.t1(a bigint, index idx_a(a));`)
+	c.Assert(err, IsNil)
+	_, err = se.Execute(ctx, `create table test.t2(a bigint, index idx_a(a));`)
+	c.Assert(err, IsNil)
+
+	_, err = se.Execute(ctx, "drop database if exists test2")
+	c.Assert(err, IsNil)
+	_, err = se.Execute(ctx, "create database test2")
+	c.Assert(err, IsNil)
+	_, err = se.Execute(ctx, "use test2")
+	c.Assert(err, IsNil)
+
+	var input []string
+	var output []struct {
+		SQL  string
+		Plan string
+	}
+	is := domain.GetDomain(se).InfoSchema()
+	s.testData.GetTestCases(c, &input, &output)
+	for i, tt := range input {
+		comment := Commentf("case:%v sql: %s", i, tt)
+		stmt, err := s.ParseOneStmt(tt, "", "")
+		c.Assert(err, IsNil, comment)
+		p, _, err := planner.Optimize(ctx, se, stmt, is)
+		c.Assert(err, IsNil, comment)
+		s.testData.OnRecord(func() {
+			output[i].SQL = tt
+			output[i].Plan = core.ToString(p)
+		})
+		c.Assert(core.ToString(p), Equals, output[i].Plan, comment)
+	}
+}
diff --git a/planner/core/planbuilder.go b/planner/core/planbuilder.go
index 0fb860f152732..79ce8f67d53f1 100644
--- a/planner/core/planbuilder.go
+++ b/planner/core/planbuilder.go
@@ -115,7 +115,7 @@ func tableNames2HintTableInfo(ctx sessionctx.Context, hintTables []ast.HintTable
 	hintTableInfos := make([]hintTableInfo, len(hintTables))
 	defaultDBName := model.NewCIStr(ctx.GetSessionVars().CurrentDB)
 	for i, hintTable := range hintTables {
-		tableInfo := hintTableInfo{tblName: hintTable.TableName, selectOffset: p.getHintOffset(hintTable.QBName, nodeType, currentOffset)}
+		tableInfo := hintTableInfo{dbName: hintTable.DBName, tblName: hintTable.TableName, selectOffset: p.getHintOffset(hintTable.QBName, nodeType, currentOffset)}
 		if tableInfo.dbName.L == "" {
 			tableInfo.dbName = defaultDBName
 		}
diff --git a/planner/core/testdata/plan_suite_in.json b/planner/core/testdata/plan_suite_in.json
index 46b68f86f9986..c4a4acc6f37fd 100644
--- a/planner/core/testdata/plan_suite_in.json
+++ b/planner/core/testdata/plan_suite_in.json
@@ -569,5 +569,11 @@
       "select /*+ INL_HASH_JOIN(t1) */ t1.b, t2.b from t1 inner join t2 on t1.a = t2.a;",
       "select /*+ INL_MERGE_JOIN(t1) */ t1.b, t2.b from t1 inner join t2 on t1.a = t2.a;"
     ]
+  },
+  {
+    "name": "TestHintFromDiffDatabase",
+    "cases": [
+      "select /*+ inl_hash_join(test.t1) */ * from test.t2 join test.t1 on test.t2.a = test.t1.a"
+    ]
   }
 ]
diff --git a/planner/core/testdata/plan_suite_out.json b/planner/core/testdata/plan_suite_out.json
index 748eed8b65186..6ba675d4faf10 100644
--- a/planner/core/testdata/plan_suite_out.json
+++ b/planner/core/testdata/plan_suite_out.json
@@ -1661,5 +1661,14 @@
         "Hints": "USE_INDEX(@`sel_1` `test`.`t1` `idx_a`), USE_INDEX(@`sel_1` `test`.`t2` )"
       }
     ]
+  },
+  {
+    "Name": "TestHintFromDiffDatabase",
+    "Cases": [
+      {
+        "SQL": "select /*+ inl_hash_join(test.t1) */ * from test.t2 join test.t1 on test.t2.a = test.t1.a",
+        "Plan": "IndexHashJoin{IndexReader(Index(t2.idx_a)[[-inf,+inf]])->IndexReader(Index(t1.idx_a)[[NULL,+inf]]->Sel([not(isnull(test.t1.a))]))}(test.t2.a,test.t1.a)"
+      }
+    ]
   }
 ]