br: add foreign key test for br (#39427)

br/pkg/gluetidb/glue.go

@@ -208,6 +208,8 @@ func (gs *tidbSession) CreateTables(ctx context.Context, tables map[string][]*mo
 	d := domain.GetDomain(gs.se).DDL()
 	var dbName model.CIStr
 
+	// Disable foreign key check when batch create tables.
+	gs.se.GetSessionVars().ForeignKeyChecks = false
 	for db, tablesInDB := range tables {
 		dbName = model.NewCIStr(db)
 		queryBuilder := strings.Builder{}

br/tests/br_foreign_key/run.sh

@@ -0,0 +1,55 @@
+#!/bin/sh
+#
+# Copyright 2022 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.
+
+set -eu
+DB="$TEST_NAME"
+
+run_sql "set @@global.tidb_enable_foreign_key=1;"
+run_sql "set @@global.foreign_key_checks=1;"
+run_sql "set @@foreign_key_checks=1;"
+run_sql "create schema $DB;"
+run_sql "create table $DB.t1 (id int key);"
+run_sql "create table $DB.t2 (id int key, a int, b int, foreign key fk_1 (a) references t1(id) ON UPDATE SET NULL ON DELETE SET NULL, foreign key fk_2 (b) references t1(id) ON DELETE CASCADE ON UPDATE CASCADE);"
+run_sql "insert into $DB.t1 values (1), (2), (3);"
+run_sql "insert into $DB.t2 values (1, 1, 1), (2, 2, 2), (3, 3, 3);"
+run_sql "update $DB.t1 set id=id+10 where id in (1, 3);"
+run_sql "delete from $DB.t1 where id = 2;"
+
+echo "backup start..."
+run_br backup db --db "$DB" -s "local://$TEST_DIR/$DB" --pd $PD_ADDR
+
+run_sql "drop schema $DB;"
+
+echo "restore start..."
+run_br restore db --db $DB -s "local://$TEST_DIR/$DB" --pd $PD_ADDR
+
+set -x
+
+run_sql "select count(*) from $DB.t1;"
+check_contains 'count(*): 2'
+
+run_sql "select count(*) from $DB.t2;"
+check_contains 'count(*): 2'
+
+run_sql "select id, a, b from $DB.t2;"
+check_contains 'id: 1'
+check_contains 'id: 3'
+check_contains 'a: NULL'
+check_contains 'b: 11'
+check_contains 'b: 13'
+check_contains 'b: 14'
+
+run_sql "drop schema $DB"