From 67d8fbf23eee71f8b6ddc4221e7bf8bdc5fdad9f Mon Sep 17 00:00:00 2001
From: pingcap-github-bot <sre-bot@pingcap.com>
Date: Fri, 18 Oct 2019 17:40:50 +0800
Subject: [PATCH] planner: support foreign key choose parent schema as default
 in CreateTable stmt  (#12548) (#12675)

---
 ddl/db_integration_test.go | 11 +++++++++++
 planner/core/preprocess.go |  9 +++++++++
 2 files changed, 20 insertions(+)

diff --git a/ddl/db_integration_test.go b/ddl/db_integration_test.go
index 52fd0f40a208f..7353e57abf6f8 100644
--- a/ddl/db_integration_test.go
+++ b/ddl/db_integration_test.go
@@ -1992,3 +1992,14 @@ func (s *testIntegrationSuite4) TestDropAutoIncrementIndex(c *C) {
 	dropIndexSQL = "alter table t1 drop index a"
 	assertErrorCode(c, tk, dropIndexSQL, mysql.ErrWrongAutoKey)
 }
+
+func (s *testIntegrationSuite3) TestParserIssue284(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec("create table test.t_parser_issue_284(c1 int not null primary key)")
+	_, err := tk.Exec("create table test.t_parser_issue_284_2(id int not null primary key, c1 int not null, constraint foreign key (c1) references t_parser_issue_284(c1))")
+	c.Assert(err, IsNil)
+
+	tk.MustExec("drop table test.t_parser_issue_284")
+	tk.MustExec("drop table test.t_parser_issue_284_2")
+}
diff --git a/planner/core/preprocess.go b/planner/core/preprocess.go
index 662c9f74df11b..3ef613bb48995 100644
--- a/planner/core/preprocess.go
+++ b/planner/core/preprocess.go
@@ -85,6 +85,7 @@ func (p *preprocessor) Enter(in ast.Node) (out ast.Node, skipChildren bool) {
 	switch node := in.(type) {
 	case *ast.CreateTableStmt:
 		p.flag |= inCreateOrDropTable
+		p.resolveCreateTableStmt(node)
 		p.checkCreateTableGrammar(node)
 	case *ast.CreateViewStmt:
 		p.flag |= inCreateOrDropTable
@@ -738,6 +739,14 @@ func (p *preprocessor) resolveShowStmt(node *ast.ShowStmt) {
 	}
 }
 
+func (p *preprocessor) resolveCreateTableStmt(node *ast.CreateTableStmt) {
+	for _, val := range node.Constraints {
+		if val.Refer != nil && val.Refer.Table.Schema.String() == "" {
+			val.Refer.Table.Schema = node.Table.Schema
+		}
+	}
+}
+
 func (p *preprocessor) resolveAlterTableStmt(node *ast.AlterTableStmt) {
 	for _, spec := range node.Specs {
 		if spec.Tp == ast.AlterTableRenameTable {