From d2b5387183a591847f952aa4e3a3c4597c34dcba Mon Sep 17 00:00:00 2001
From: crazycs <crazycs520@gmail.com>
Date: Fri, 2 Aug 2019 15:03:24 +0800
Subject: [PATCH] infoschema: fix load drop database schema bug and refine
 db-table api error.  (#11573)

---
 infoschema/builder.go     | 12 ++++++------
 infoschema/tables_test.go | 20 ++++++++++++++++++++
 server/http_handler.go    |  4 ++--
 3 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/infoschema/builder.go b/infoschema/builder.go
index 7b90e1f23cd12..72d0d9ce29e72 100644
--- a/infoschema/builder.go
+++ b/infoschema/builder.go
@@ -154,22 +154,22 @@ func (b *Builder) applyDropSchema(schemaID int64) []int64 {
 	delete(b.is.schemaMap, di.Name.L)
 
 	// Copy the sortedTables that contain the table we are going to drop.
+	tableIDs := make([]int64, 0, len(di.Tables))
 	bucketIdxMap := make(map[int]struct{})
 	for _, tbl := range di.Tables {
 		bucketIdxMap[tableBucketIdx(tbl.ID)] = struct{}{}
+		// TODO: If the table ID doesn't exist.
+		tableIDs = append(tableIDs, tbl.ID)
 	}
 	for bucketIdx := range bucketIdxMap {
 		b.copySortedTablesBucket(bucketIdx)
 	}
 
-	ids := make([]int64, 0, len(di.Tables))
 	di = di.Clone()
-	for _, tbl := range di.Tables {
-		b.applyDropTable(di, tbl.ID)
-		// TODO: If the table ID doesn't exist.
-		ids = append(ids, tbl.ID)
+	for _, id := range tableIDs {
+		b.applyDropTable(di, id)
 	}
-	return ids
+	return tableIDs
 }
 
 func (b *Builder) copySortedTablesBucket(bucketIdx int) {
diff --git a/infoschema/tables_test.go b/infoschema/tables_test.go
index c2c7c84cb1ea5..13fa50cf8d15b 100644
--- a/infoschema/tables_test.go
+++ b/infoschema/tables_test.go
@@ -22,7 +22,9 @@ import (
 
 	. "github.com/pingcap/check"
 	"github.com/pingcap/parser/auth"
+	"github.com/pingcap/parser/model"
 	"github.com/pingcap/parser/mysql"
+	"github.com/pingcap/parser/terror"
 	"github.com/pingcap/tidb/domain"
 	"github.com/pingcap/tidb/infoschema"
 	"github.com/pingcap/tidb/kv"
@@ -525,3 +527,21 @@ func (s *testTableSuite) TestColumnStatistics(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	tk.MustQuery("select * from information_schema.column_statistics").Check(testkit.Rows())
 }
+
+func (s *testTableSuite) TestReloadDropDatabase(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("create database test_dbs")
+	tk.MustExec("use test_dbs")
+	tk.MustExec("create table t1 (a int)")
+	tk.MustExec("create table t2 (a int)")
+	tk.MustExec("create table t3 (a int)")
+	is := domain.GetDomain(tk.Se).InfoSchema()
+	t2, err := is.TableByName(model.NewCIStr("test_dbs"), model.NewCIStr("t2"))
+	c.Assert(err, IsNil)
+	tk.MustExec("drop database test_dbs")
+	is = domain.GetDomain(tk.Se).InfoSchema()
+	_, err = is.TableByName(model.NewCIStr("test_dbs"), model.NewCIStr("t2"))
+	c.Assert(terror.ErrorEqual(infoschema.ErrTableNotExists, err), IsTrue)
+	_, ok := is.TableByID(t2.Meta().ID)
+	c.Assert(ok, IsFalse)
+}
diff --git a/server/http_handler.go b/server/http_handler.go
index 446cd027b3a84..3c59ea613901e 100644
--- a/server/http_handler.go
+++ b/server/http_handler.go
@@ -1531,8 +1531,8 @@ func (h dbTableHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 		dbTblInfo.TableInfo = tbl.Meta()
 		dbInfo, ok := schema.SchemaByTable(dbTblInfo.TableInfo)
 		if !ok {
-			log.Warnf("can not find the database of table id: %v, table name: %v", dbTblInfo.TableInfo.ID, dbTblInfo.TableInfo.Name)
-			writeData(w, dbTblInfo)
+			logutil.BgLogger().Error("can not find the database of the table", zap.Int64("table id", dbTblInfo.TableInfo.ID), zap.String("table name", dbTblInfo.TableInfo.Name.L))
+			writeError(w, infoschema.ErrTableNotExists.GenWithStack("Table which ID = %s does not exist.", tableID))
 			return
 		}
 		dbTblInfo.DBInfo = dbInfo