executor: add DROP ROLE support

executor/simple.go

@@ -300,6 +300,44 @@ func (e *SimpleExec) executeDropUser(s *ast.DropUserStmt) error {
 			continue
 		}
 
+		// delete relationship from mysql.role_edges
+		sql = fmt.Sprintf(`DELETE FROM %s.%s WHERE TO_HOST = '%s' and TO_USER = '%s';`, mysql.SystemDB, mysql.RoleEdgeTable, user.Hostname, user.Username)
+		if _, err := e.ctx.(sqlexec.SQLExecutor).Execute(context.Background(), sql); err != nil {
+			failedUsers = append(failedUsers, user.String())
+			if _, err := e.ctx.(sqlexec.SQLExecutor).Execute(context.Background(), "rollback"); err != nil {
+				return errors.Trace(err)
+			}
+			continue
+		}
+
+		sql = fmt.Sprintf(`DELETE FROM %s.%s WHERE FROM_HOST = '%s' and FROM_USER = '%s';`, mysql.SystemDB, mysql.RoleEdgeTable, user.Hostname, user.Username)
+		if _, err := e.ctx.(sqlexec.SQLExecutor).Execute(context.Background(), sql); err != nil {
+			failedUsers = append(failedUsers, user.String())
+			if _, err := e.ctx.(sqlexec.SQLExecutor).Execute(context.Background(), "rollback"); err != nil {
+				return errors.Trace(err)
+			}
+			continue
+		}
+
+		// delete relationship from mysql.default_roles
+		sql = fmt.Sprintf(`DELETE FROM %s.%s WHERE DEFAULT_ROLE_HOST = '%s' and DEFAULT_ROLE_USER = '%s';`, mysql.SystemDB, mysql.DefaultRoleTable, user.Hostname, user.Username)
+		if _, err := e.ctx.(sqlexec.SQLExecutor).Execute(context.Background(), sql); err != nil {
+			failedUsers = append(failedUsers, user.String())
+			if _, err := e.ctx.(sqlexec.SQLExecutor).Execute(context.Background(), "rollback"); err != nil {
+				return errors.Trace(err)
+			}
+			continue
+		}
+
+		sql = fmt.Sprintf(`DELETE FROM %s.%s WHERE HOST = '%s' and USER = '%s';`, mysql.SystemDB, mysql.DefaultRoleTable, user.Hostname, user.Username)
+		if _, err := e.ctx.(sqlexec.SQLExecutor).Execute(context.Background(), sql); err != nil {
+			failedUsers = append(failedUsers, user.String())
+			if _, err := e.ctx.(sqlexec.SQLExecutor).Execute(context.Background(), "rollback"); err != nil {
+				return errors.Trace(err)
+			}
+			continue
+		}
+
 		//TODO: need delete columns_priv once we implement columns_priv functionality.
 		if _, err := e.ctx.(sqlexec.SQLExecutor).Execute(context.Background(), "commit"); err != nil {
 			failedUsers = append(failedUsers, user.String())

executor/simple_test.go

@@ -87,6 +87,40 @@ func inTxn(ctx sessionctx.Context) bool {
 	return (ctx.GetSessionVars().Status & mysql.ServerStatusInTrans) > 0
 }
 
+func (s *testSuite3) TestRole(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	// Make sure user test not in mysql.User.
+	result := tk.MustQuery(`SELECT Password FROM mysql.User WHERE User="test" and Host="localhost"`)
+	result.Check(nil)
+
+	createRoleSQL := `CREATE ROLE 'test'@'localhost';`
+	tk.MustExec(createRoleSQL)
+	// Make sure user test in mysql.User.
+	result = tk.MustQuery(`SELECT Password FROM mysql.User WHERE User="test" and Host="localhost"`)
+	result.Check(testkit.Rows(auth.EncodePassword("")))
+	// Insert relation into mysql.role_edges
+	tk.MustExec("insert into mysql.role_edges (FROM_HOST,FROM_USER,TO_HOST,TO_USER) values ('localhost','test','%','root')")
+	tk.MustExec("insert into mysql.role_edges (FROM_HOST,FROM_USER,TO_HOST,TO_USER) values ('localhost','test1','localhost','test1')")
+	// Insert relation into mysql.default_roles
+	tk.MustExec("insert into mysql.default_roles (HOST,USER,DEFAULT_ROLE_HOST,DEFAULT_ROLE_USER) values ('%','root','localhost','test')")
+	tk.MustExec("insert into mysql.default_roles (HOST,USER,DEFAULT_ROLE_HOST,DEFAULT_ROLE_USER) values ('localhost','test','%','test1')")
+
+	dropUserSQL := `DROP ROLE IF EXISTS 'test'@'localhost' ;`
+	_, err := tk.Exec(dropUserSQL)
+	c.Check(err, IsNil)
+
+	result = tk.MustQuery(`SELECT Password FROM mysql.User WHERE User="test" and Host="localhost"`)
+	result.Check(nil)
+	result = tk.MustQuery(`SELECT * FROM mysql.role_edges WHERE TO_USER="test" and TO_HOST="localhost"`)
+	result.Check(nil)
+	result = tk.MustQuery(`SELECT * FROM mysql.role_edges WHERE FROM_USER="test" and FROM_HOST="localhost"`)
+	result.Check(nil)
+	result = tk.MustQuery(`SELECT * FROM mysql.default_roles WHERE USER="test" and HOST="localhost"`)
+	result.Check(nil)
+	result = tk.MustQuery(`SELECT * FROM mysql.default_roles WHERE DEFAULT_ROLE_USER="test" and DEFAULT_ROLE_HOST="localhost"`)
+	result.Check(nil)
+}
+
 func (s *testSuite3) TestUser(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	// Make sure user test not in mysql.User.

go.mod

@@ -49,7 +49,7 @@ require (
 	github.com/pingcap/goleveldb v0.0.0-20171020122428-b9ff6c35079e
 	github.com/pingcap/kvproto v0.0.0-20190215154024-7f2fc73ef562
 	github.com/pingcap/log v0.0.0-20190307075452-bd41d9273596
-	github.com/pingcap/parser v0.0.0-20190311093336-9fca026d9c49
+	github.com/pingcap/parser v0.0.0-20190312024907-3f6280b08c8b
 	github.com/pingcap/pd v2.1.0-rc.4+incompatible
 	github.com/pingcap/tidb-tools v2.1.3-0.20190116051332-34c808eef588+incompatible
 	github.com/pingcap/tipb v0.0.0-20190107072121-abbec73437b7

go.sum

@@ -113,8 +113,8 @@ github.com/pingcap/kvproto v0.0.0-20190215154024-7f2fc73ef562 h1:32oF1/8lVnBR2JV
 github.com/pingcap/kvproto v0.0.0-20190215154024-7f2fc73ef562/go.mod h1:QMdbTAXCHzzygQzqcG9uVUgU2fKeSN1GmfMiykdSzzY=
 github.com/pingcap/log v0.0.0-20190307075452-bd41d9273596 h1:t2OQTpPJnrPDGlvA+3FwJptMTt6MEPdzK1Wt99oaefQ=
 github.com/pingcap/log v0.0.0-20190307075452-bd41d9273596/go.mod h1:WpHUKhNZ18v116SvGrmjkA9CBhYmuUTKL+p8JC9ANEw=
-github.com/pingcap/parser v0.0.0-20190311093336-9fca026d9c49 h1:dnac5Z4hlmf8Ocd+RasmkuEuI0ZJRH+QJAh3K6vMySQ=
-github.com/pingcap/parser v0.0.0-20190311093336-9fca026d9c49/go.mod h1:1FNvfp9+J0wvc4kl8eGNh7Rqrxveg15jJoWo/a0uHwA=
+github.com/pingcap/parser v0.0.0-20190312024907-3f6280b08c8b h1:NlvTrxqezIJh6CD5Leky12IZ8E/GtpEEmzgNNb34wbw=
+github.com/pingcap/parser v0.0.0-20190312024907-3f6280b08c8b/go.mod h1:1FNvfp9+J0wvc4kl8eGNh7Rqrxveg15jJoWo/a0uHwA=
 github.com/pingcap/pd v2.1.0-rc.4+incompatible h1:/buwGk04aHO5odk/+O8ZOXGs4qkUjYTJ2UpCJXna8NE=
 github.com/pingcap/pd v2.1.0-rc.4+incompatible/go.mod h1:nD3+EoYes4+aNNODO99ES59V83MZSI+dFbhyr667a0E=
 github.com/pingcap/tidb-tools v2.1.3-0.20190116051332-34c808eef588+incompatible h1:e9Gi/LP9181HT3gBfSOeSBA+5JfemuE4aEAhqNgoE4k=

planner/core/planbuilder.go

@@ -1019,7 +1019,15 @@ func (b *PlanBuilder) buildSimple(node ast.StmtNode) (Plan, error) {
 			err := ErrSpecificAccessDenied.GenWithStackByArgs("CREATE USER")
 			b.visitInfo = appendVisitInfo(b.visitInfo, mysql.CreateUserPriv, "", "", "", err)
 		}
-	case *ast.DropUserStmt, *ast.AlterUserStmt:
+	case *ast.DropUserStmt:
+		if raw.IsDropRole {
+			err := ErrSpecificAccessDenied.GenWithStackByArgs("DROP ROLE")
+			b.visitInfo = appendVisitInfo(b.visitInfo, mysql.DropRolePriv, "", "", "", err)
+		} else {
+			err := ErrSpecificAccessDenied.GenWithStackByArgs("CREATE USER")
+			b.visitInfo = appendVisitInfo(b.visitInfo, mysql.CreateUserPriv, "", "", "", err)
+		}
+	case *ast.AlterUserStmt:
 		err := ErrSpecificAccessDenied.GenWithStackByArgs("CREATE USER")
 		b.visitInfo = appendVisitInfo(b.visitInfo, mysql.CreateUserPriv, "", "", "", err)
 	case *ast.GrantStmt: