diff --git a/ddl/db_integration_test.go b/ddl/db_integration_test.go
index 9c469db3a12db..d9a0ab1f6fd89 100644
--- a/ddl/db_integration_test.go
+++ b/ddl/db_integration_test.go
@@ -272,7 +272,7 @@ func (s *testIntegrationSuite2) TestIssue6101(c *C) {
 	tk.MustExec("create table t1 (quantity decimal(2) unsigned);")
 	_, err := tk.Exec("insert into t1 values (500), (-500), (~0), (-1);")
 	terr := errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(errno.ErrWarnDataOutOfRange))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(errno.ErrWarnDataOutOfRange))
 	tk.MustExec("drop table t1")
 
 	tk.MustExec("set sql_mode=''")
diff --git a/domain/domain_test.go b/domain/domain_test.go
index b065c86e52428..1a2618d550c5a 100644
--- a/domain/domain_test.go
+++ b/domain/domain_test.go
@@ -27,7 +27,6 @@ import (
 	"github.com/pingcap/failpoint"
 	"github.com/pingcap/parser/ast"
 	"github.com/pingcap/parser/model"
-	"github.com/pingcap/parser/terror"
 	"github.com/pingcap/tidb/ddl"
 	"github.com/pingcap/tidb/domain/infosync"
 	"github.com/pingcap/tidb/errno"
@@ -459,6 +458,6 @@ func (*testSuite) TestSessionPool(c *C) {
 }
 
 func (*testSuite) TestErrorCode(c *C) {
-	c.Assert(int(terror.ToSQLError(ErrInfoSchemaExpired).Code), Equals, errno.ErrInfoSchemaExpired)
-	c.Assert(int(terror.ToSQLError(ErrInfoSchemaChanged).Code), Equals, errno.ErrInfoSchemaChanged)
+	c.Assert(int(ErrInfoSchemaExpired.ToSQLError().Code), Equals, errno.ErrInfoSchemaExpired)
+	c.Assert(int(ErrInfoSchemaChanged.ToSQLError().Code), Equals, errno.ErrInfoSchemaChanged)
 }
diff --git a/executor/executor_test.go b/executor/executor_test.go
index 7708e1f4f4b79..1a4af061f395c 100644
--- a/executor/executor_test.go
+++ b/executor/executor_test.go
@@ -1248,12 +1248,12 @@ func (s *testSuiteP2) TestUnion(c *C) {
 	err := tk.ExecToErr("select 1 from (select a from t limit 1 union all select a from t limit 1) tmp")
 	c.Assert(err, NotNil)
 	terr := errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.ErrWrongUsage))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.ErrWrongUsage))
 
 	err = tk.ExecToErr("select 1 from (select a from t order by a union all select a from t limit 1) tmp")
 	c.Assert(err, NotNil)
 	terr = errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.ErrWrongUsage))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.ErrWrongUsage))
 
 	_, err = tk.Exec("(select a from t order by a) union all select a from t limit 1 union all select a from t limit 1")
 	c.Assert(terror.ErrorEqual(err, plannercore.ErrWrongUsage), IsTrue, Commentf("err %v", err))
@@ -1642,23 +1642,23 @@ func (s *testSuiteP1) TestJSON(c *C) {
 	_, err = tk.Exec(`create table test_bad_json(a json default '{}')`)
 	c.Assert(err, NotNil)
 	terr = errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.ErrBlobCantHaveDefault))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.ErrBlobCantHaveDefault))
 
 	_, err = tk.Exec(`create table test_bad_json(a blob default 'hello')`)
 	c.Assert(err, NotNil)
 	terr = errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.ErrBlobCantHaveDefault))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.ErrBlobCantHaveDefault))
 
 	_, err = tk.Exec(`create table test_bad_json(a text default 'world')`)
 	c.Assert(err, NotNil)
 	terr = errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.ErrBlobCantHaveDefault))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.ErrBlobCantHaveDefault))
 
 	// check json fields cannot be used as key.
 	_, err = tk.Exec(`create table test_bad_json(id int, a json, key (a))`)
 	c.Assert(err, NotNil)
 	terr = errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.ErrJSONUsedAsKey))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.ErrJSONUsedAsKey))
 
 	// check CAST AS JSON.
 	result = tk.MustQuery(`select CAST('3' AS JSON), CAST('{}' AS JSON), CAST(null AS JSON)`)
@@ -1756,7 +1756,7 @@ func (s *testSuiteP1) TestGeneratedColumnWrite(c *C) {
 		if tt.err != 0 {
 			c.Assert(err, NotNil, Commentf("sql is `%v`", tt.stmt))
 			terr := errors.Cause(err).(*terror.Error)
-			c.Assert(terr.Code(), Equals, errors.ErrCode(tt.err), Commentf("sql is %v", tt.stmt))
+			c.Assert(terr.Code(), Equals, terror.ErrCode(tt.err), Commentf("sql is %v", tt.stmt))
 		} else {
 			c.Assert(err, IsNil)
 		}
@@ -1927,7 +1927,7 @@ func (s *testSuiteP1) TestGeneratedColumnRead(c *C) {
 		if tt.err != 0 {
 			c.Assert(err, NotNil)
 			terr := errors.Cause(err).(*terror.Error)
-			c.Assert(terr.Code(), Equals, errors.ErrCode(tt.err))
+			c.Assert(terr.Code(), Equals, terror.ErrCode(tt.err))
 		} else {
 			c.Assert(err, IsNil)
 		}
@@ -3295,7 +3295,7 @@ func (s *testSuite) TestContainDotColumn(c *C) {
 	tk.MustExec("drop table if exists t3")
 	_, err := tk.Exec("create table t3(s.a char);")
 	terr := errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.ErrWrongTableName))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.ErrWrongTableName))
 }
 
 func (s *testSuite) TestCheckIndex(c *C) {
@@ -4213,7 +4213,7 @@ func (s *testSuiteP2) TestSplitRegion(c *C) {
 	_, err := tk.Exec(`split table t index idx1 by ("abcd");`)
 	c.Assert(err, NotNil)
 	terr := errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.WarnDataTruncated))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.WarnDataTruncated))
 
 	// Test for split index region.
 	// Check min value is more than max value.
@@ -5956,7 +5956,7 @@ func (s *testSplitTable) TestKillTableReader(c *C) {
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
-		c.Assert(int(terror.ToSQLError(errors.Cause(tk.QueryToErr("select * from t")).(*terror.Error)).Code), Equals, int(executor.ErrQueryInterrupted.Code()))
+		c.Assert(int(errors.Cause(tk.QueryToErr("select * from t")).(*terror.Error).ToSQLError().Code), Equals, int(executor.ErrQueryInterrupted.Code()))
 	}()
 	time.Sleep(1 * time.Second)
 	atomic.StoreUint32(&tk.Se.GetSessionVars().Killed, 1)
diff --git a/executor/show.go b/executor/show.go
index 305f3172a4ec5..dea0ead1f0e42 100644
--- a/executor/show.go
+++ b/executor/show.go
@@ -1338,7 +1338,7 @@ func (e *ShowExec) fetchShowWarnings(errOnly bool) error {
 		warn := errors.Cause(w.Err)
 		switch x := warn.(type) {
 		case *terror.Error:
-			sqlErr := terror.ToSQLError(x)
+			sqlErr := x.ToSQLError()
 			e.appendRow([]interface{}{w.Level, int64(sqlErr.Code), sqlErr.Message})
 		default:
 			e.appendRow([]interface{}{w.Level, int64(mysql.ErrUnknown), warn.Error()})
diff --git a/executor/trace.go b/executor/trace.go
index bf9150f357081..3d0e787db5b55 100644
--- a/executor/trace.go
+++ b/executor/trace.go
@@ -137,7 +137,7 @@ func (e *TraceExec) executeChild(ctx context.Context, se sqlexec.SQLExecutor) {
 		if err != nil {
 			var errCode uint16
 			if te, ok := err.(*terror.Error); ok {
-				errCode = terror.ToSQLError(te).Code
+				errCode = te.ToSQLError().Code
 			}
 			logutil.Eventf(ctx, "execute with error(%d): %s", errCode, err.Error())
 		} else {
@@ -161,7 +161,7 @@ func drainRecordSet(ctx context.Context, sctx sessionctx.Context, rs sqlexec.Rec
 			if err != nil {
 				var errCode uint16
 				if te, ok := err.(*terror.Error); ok {
-					errCode = terror.ToSQLError(te).Code
+					errCode = te.ToSQLError().Code
 				}
 				logutil.Eventf(ctx, "execute with error(%d): %s", errCode, err.Error())
 			} else {
diff --git a/expression/integration_test.go b/expression/integration_test.go
index 640d2d6a761f6..0281e82df9197 100755
--- a/expression/integration_test.go
+++ b/expression/integration_test.go
@@ -466,7 +466,7 @@ func (s *testIntegrationSuite2) TestMathBuiltin(c *C) {
 	_, err = session.GetRows4Test(ctx, tk.Se, rs)
 	c.Assert(err, NotNil)
 	terr := errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.ErrDataOutOfRange))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.ErrDataOutOfRange))
 	c.Assert(rs.Close(), IsNil)
 
 	//for exp
@@ -479,7 +479,7 @@ func (s *testIntegrationSuite2) TestMathBuiltin(c *C) {
 	_, err = session.GetRows4Test(ctx, tk.Se, rs)
 	c.Assert(err, NotNil)
 	terr = errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.ErrDataOutOfRange))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.ErrDataOutOfRange))
 	c.Assert(rs.Close(), IsNil)
 	tk.MustExec("drop table if exists t")
 	tk.MustExec("create table t(a float)")
@@ -489,7 +489,7 @@ func (s *testIntegrationSuite2) TestMathBuiltin(c *C) {
 	_, err = session.GetRows4Test(ctx, tk.Se, rs)
 	c.Assert(err, NotNil)
 	terr = errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.ErrDataOutOfRange))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.ErrDataOutOfRange))
 	c.Assert(err.Error(), Equals, "[types:1690]DOUBLE value is out of range in 'exp(test.t.a)'")
 	c.Assert(rs.Close(), IsNil)
 
@@ -529,7 +529,7 @@ func (s *testIntegrationSuite2) TestMathBuiltin(c *C) {
 	_, err = session.GetRows4Test(ctx, tk.Se, rs)
 	c.Assert(err, NotNil)
 	terr = errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.ErrDataOutOfRange))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.ErrDataOutOfRange))
 	c.Assert(rs.Close(), IsNil)
 
 	// for round
@@ -608,7 +608,7 @@ func (s *testIntegrationSuite2) TestMathBuiltin(c *C) {
 	_, err = session.GetRows4Test(ctx, tk.Se, rs)
 	c.Assert(err, NotNil)
 	terr = errors.Cause(err).(*terror.Error)
-	c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.ErrDataOutOfRange))
+	c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.ErrDataOutOfRange))
 	c.Assert(rs.Close(), IsNil)
 
 	// for sign
@@ -1226,7 +1226,7 @@ func (s *testIntegrationSuite2) TestEncryptionBuiltin(c *C) {
 		_, err = session.GetRows4Test(ctx, tk.Se, rs)
 		c.Assert(err, NotNil, Commentf("%v", len))
 		terr := errors.Cause(err).(*terror.Error)
-		c.Assert(terr.Code(), Equals, errors.ErrCode(mysql.ErrDataOutOfRange), Commentf("%v", len))
+		c.Assert(terr.Code(), Equals, terror.ErrCode(mysql.ErrDataOutOfRange), Commentf("%v", len))
 		c.Assert(rs.Close(), IsNil)
 	}
 	tk.MustQuery("SELECT RANDOM_BYTES('1');")
@@ -3691,7 +3691,7 @@ func (s *testIntegrationSuite) TestAggregationBuiltinGroupConcat(c *C) {
 	tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Warning 1260 Some rows were cut by GROUPCONCAT(test.t.a)"))
 
 	_, err := tk.Exec("insert into d select group_concat(a) from t")
-	c.Assert(errors.Cause(err).(*terror.Error).Code(), Equals, errors.ErrCode(mysql.ErrCutValueGroupConcat))
+	c.Assert(errors.Cause(err).(*terror.Error).Code(), Equals, terror.ErrCode(mysql.ErrCutValueGroupConcat))
 
 	tk.Exec("set sql_mode=''")
 	tk.MustExec("insert into d select group_concat(a) from t")
diff --git a/go.mod b/go.mod
index 7d9e7fa16ef02..9c50b701ff791 100644
--- a/go.mod
+++ b/go.mod
@@ -32,7 +32,7 @@ require (
 	github.com/pingcap/goleveldb v0.0.0-20191226122134-f82aafb29989
 	github.com/pingcap/kvproto v0.0.0-20200818080353-7aaed8998596
 	github.com/pingcap/log v0.0.0-20200828042413-fce0951f1463
-	github.com/pingcap/parser v0.0.0-20200908132759-b65348b6244c
+	github.com/pingcap/parser v0.0.0-20200911054040-258297116c4b
 	github.com/pingcap/sysutil v0.0.0-20200715082929-4c47bcac246a
 	github.com/pingcap/tidb-tools v4.0.6-0.20200828085514-03575b185007+incompatible
 	github.com/pingcap/tipb v0.0.0-20200618092958-4fad48b4c8c3
diff --git a/go.sum b/go.sum
index d6cec4b861e86..97ab05dc79471 100644
--- a/go.sum
+++ b/go.sum
@@ -461,8 +461,8 @@ github.com/pingcap/parser v0.0.0-20200603032439-c4ecb4508d2f/go.mod h1:9v0Edh8Ib
 github.com/pingcap/parser v0.0.0-20200623164729-3a18f1e5dceb/go.mod h1:vQdbJqobJAgFyiRNNtXahpMoGWwPEuWciVEK5A20NS0=
 github.com/pingcap/parser v0.0.0-20200803072748-fdf66528323d/go.mod h1:vQdbJqobJAgFyiRNNtXahpMoGWwPEuWciVEK5A20NS0=
 github.com/pingcap/parser v0.0.0-20200901062802-475ea5e2e0a7/go.mod h1:vQdbJqobJAgFyiRNNtXahpMoGWwPEuWciVEK5A20NS0=
-github.com/pingcap/parser v0.0.0-20200908132759-b65348b6244c h1:oJn1X+lZwG4LG2DV+73lppFfnfy+3wXUwpoVgtIOQq8=
-github.com/pingcap/parser v0.0.0-20200908132759-b65348b6244c/go.mod h1:RlLfMRJwFBSiXd2lUaWdV5pSXtrpyvZM8k5bbZWsheU=
+github.com/pingcap/parser v0.0.0-20200911054040-258297116c4b h1:olNvO8UWo7Y+t2oWwB46cDj5pyqosgiQts5t8tZlbSc=
+github.com/pingcap/parser v0.0.0-20200911054040-258297116c4b/go.mod h1:vQdbJqobJAgFyiRNNtXahpMoGWwPEuWciVEK5A20NS0=
 github.com/pingcap/pd/v4 v4.0.0-rc.1.0.20200422143320-428acd53eba2/go.mod h1:s+utZtXDznOiL24VK0qGmtoHjjXNsscJx3m1n8cC56s=
 github.com/pingcap/pd/v4 v4.0.0-rc.2.0.20200520083007-2c251bd8f181/go.mod h1:q4HTx/bA8aKBa4S7L+SQKHvjRPXCRV0tA0yRw0qkZSA=
 github.com/pingcap/pd/v4 v4.0.5-0.20200817114353-e465cafe8a91 h1:zCOWP+kIzM6ZsXdu2QoM/W6+3vFZj04MYboMP2Obc0E=
@@ -609,7 +609,6 @@ github.com/ugorji/go/codec v1.1.5-pre/go.mod h1:tULtS6Gy1AE1yCENaw4Vb//HLH5njI2t
 github.com/ugorji/go/codec v1.1.7/go.mod h1:Ax+UKWsSmolVDwsd+7N3ZtXu+yMGCf907BLYF3GoBXY=
 github.com/unrolled/render v0.0.0-20171102162132-65450fb6b2d3/go.mod h1:tu82oB5W2ykJRVioYsB+IQKcft7ryBr7w12qMBUPyXg=
 github.com/urfave/cli v1.20.0/go.mod h1:70zkFmudgCuE/ngEzBv17Jvp/497gISqfk5gWijbERA=
-github.com/urfave/cli v1.22.2 h1:gsqYFH8bb9ekPA12kRo0hfjngWQjkJPlN9R0N78BoUo=
 github.com/urfave/cli v1.22.2/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtXRu0=
 github.com/urfave/cli/v2 v2.1.1/go.mod h1:SE9GqnLQmjVa0iPEY0f1w3ygNIYcIJ0OKPMoW2caLfQ=
 github.com/urfave/negroni v0.3.0/go.mod h1:Meg73S6kFm/4PpbYdq35yYWoCZ9mS/YSx+lKnmiohz4=
diff --git a/kv/error_test.go b/kv/error_test.go
index 4fd73a0fdf013..a5a608ac4849e 100644
--- a/kv/error_test.go
+++ b/kv/error_test.go
@@ -37,7 +37,7 @@ func (s testErrorSuite) TestError(c *C) {
 		ErrWriteConflictInTiDB,
 	}
 	for _, err := range kvErrs {
-		code := terror.ToSQLError(err).Code
+		code := err.ToSQLError().Code
 		c.Assert(code != mysql.ErrUnknown && code == uint16(err.Code()), IsTrue, Commentf("err: %v", err))
 	}
 }
diff --git a/metrics/server.go b/metrics/server.go
index c753f9612638b..250d35b68e061 100644
--- a/metrics/server.go
+++ b/metrics/server.go
@@ -14,6 +14,8 @@
 package metrics
 
 import (
+	"strconv"
+
 	"github.com/pingcap/errors"
 	"github.com/pingcap/parser/terror"
 	"github.com/prometheus/client_golang/prometheus"
@@ -168,7 +170,7 @@ func ExecuteErrorToLabel(err error) string {
 	err = errors.Cause(err)
 	switch x := err.(type) {
 	case *terror.Error:
-		return string(x.RFCCode())
+		return x.Class().String() + ":" + strconv.Itoa(int(x.Code()))
 	default:
 		return "unknown"
 	}
diff --git a/planner/core/errors_test.go b/planner/core/errors_test.go
index 2f17297484fe4..bce2a3563978d 100644
--- a/planner/core/errors_test.go
+++ b/planner/core/errors_test.go
@@ -84,7 +84,7 @@ func (s testErrorSuite) TestError(c *C) {
 		ErrAmbiguous,
 	}
 	for _, err := range kvErrs {
-		code := terror.ToSQLError(err).Code
+		code := err.ToSQLError().Code
 		c.Assert(code != mysql.ErrUnknown && code == uint16(err.Code()), IsTrue, Commentf("err: %v", err))
 	}
 }
diff --git a/privilege/privileges/cache.go b/privilege/privileges/cache.go
index 62284687fb929..9d7e2b4404fab 100644
--- a/privilege/privileges/cache.go
+++ b/privilege/privileges/cache.go
@@ -337,7 +337,7 @@ func (p *MySQLPrivilege) LoadAll(ctx sessionctx.Context) error {
 func noSuchTable(err error) bool {
 	e1 := errors.Cause(err)
 	if e2, ok := e1.(*terror.Error); ok {
-		if terror.ErrCode(e2.Code()) == terror.ErrCode(mysql.ErrNoSuchTable) {
+		if e2.Code() == terror.ErrCode(mysql.ErrNoSuchTable) {
 			return true
 		}
 	}
diff --git a/server/conn.go b/server/conn.go
index 406c90b9a746a..0f541376f8781 100644
--- a/server/conn.go
+++ b/server/conn.go
@@ -1008,12 +1008,12 @@ func (cc *clientConn) writeError(ctx context.Context, e error) error {
 	)
 	originErr := errors.Cause(e)
 	if te, ok = originErr.(*terror.Error); ok {
-		m = terror.ToSQLError(te)
+		m = te.ToSQLError()
 	} else {
 		e := errors.Cause(originErr)
 		switch y := e.(type) {
 		case *terror.Error:
-			m = terror.ToSQLError(y)
+			m = y.ToSQLError()
 		default:
 			m = mysql.NewErrf(mysql.ErrUnknown, "%s", e.Error())
 		}
diff --git a/sessionctx/variable/sysvar_test.go b/sessionctx/variable/sysvar_test.go
index 51c6eba70134a..eaf309db70f52 100644
--- a/sessionctx/variable/sysvar_test.go
+++ b/sessionctx/variable/sysvar_test.go
@@ -89,6 +89,6 @@ func (*testSysVarSuite) TestError(c *C) {
 		ErrUnsupportedIsolationLevel,
 	}
 	for _, err := range kvErrs {
-		c.Assert(terror.ToSQLError(err).Code != mysql.ErrUnknown, IsTrue)
+		c.Assert(err.ToSQLError().Code != mysql.ErrUnknown, IsTrue)
 	}
 }
diff --git a/store/mockstore/mocktikv/cop_handler_dag.go b/store/mockstore/mocktikv/cop_handler_dag.go
index 6692fd59011a1..086c797ee093f 100644
--- a/store/mockstore/mocktikv/cop_handler_dag.go
+++ b/store/mockstore/mocktikv/cop_handler_dag.go
@@ -814,14 +814,14 @@ func toPBError(err error) *tipb.Error {
 	perr := new(tipb.Error)
 	switch x := err.(type) {
 	case *terror.Error:
-		sqlErr := terror.ToSQLError(x)
+		sqlErr := x.ToSQLError()
 		perr.Code = int32(sqlErr.Code)
 		perr.Msg = sqlErr.Message
 	default:
 		e := errors.Cause(err)
 		switch y := e.(type) {
 		case *terror.Error:
-			tmp := terror.ToSQLError(y)
+			tmp := y.ToSQLError()
 			perr.Code = int32(tmp.Code)
 			perr.Msg = tmp.Message
 		default:
diff --git a/structure/structure_test.go b/structure/structure_test.go
index 53c7e0dbfb33e..62fdeb8f60159 100644
--- a/structure/structure_test.go
+++ b/structure/structure_test.go
@@ -406,7 +406,7 @@ func (*testTxStructureSuite) TestError(c *C) {
 		structure.ErrWriteOnSnapshot,
 	}
 	for _, err := range kvErrs {
-		code := terror.ToSQLError(err).Code
+		code := err.ToSQLError().Code
 		c.Assert(code != mysql.ErrUnknown && code == uint16(err.Code()), IsTrue, Commentf("err: %v", err))
 	}
 }
diff --git a/table/table_test.go b/table/table_test.go
index edcfc7d3c2bc9..d3d0e5edd172c 100644
--- a/table/table_test.go
+++ b/table/table_test.go
@@ -15,7 +15,6 @@ package table
 
 import (
 	. "github.com/pingcap/check"
-	"github.com/pingcap/parser/terror"
 	mysql "github.com/pingcap/tidb/errno"
 )
 
@@ -31,21 +30,21 @@ func (t *testTableSuite) TestSlice(c *C) {
 }
 
 func (t *testTableSuite) TestErrorCode(c *C) {
-	c.Assert(int(terror.ToSQLError(ErrColumnCantNull).Code), Equals, mysql.ErrBadNull)
-	c.Assert(int(terror.ToSQLError(ErrUnknownColumn).Code), Equals, mysql.ErrBadField)
-	c.Assert(int(terror.ToSQLError(errDuplicateColumn).Code), Equals, mysql.ErrFieldSpecifiedTwice)
-	c.Assert(int(terror.ToSQLError(errGetDefaultFailed).Code), Equals, mysql.ErrFieldGetDefaultFailed)
-	c.Assert(int(terror.ToSQLError(ErrNoDefaultValue).Code), Equals, mysql.ErrNoDefaultForField)
-	c.Assert(int(terror.ToSQLError(ErrIndexOutBound).Code), Equals, mysql.ErrIndexOutBound)
-	c.Assert(int(terror.ToSQLError(ErrUnsupportedOp).Code), Equals, mysql.ErrUnsupportedOp)
-	c.Assert(int(terror.ToSQLError(ErrRowNotFound).Code), Equals, mysql.ErrRowNotFound)
-	c.Assert(int(terror.ToSQLError(ErrTableStateCantNone).Code), Equals, mysql.ErrTableStateCantNone)
-	c.Assert(int(terror.ToSQLError(ErrColumnStateCantNone).Code), Equals, mysql.ErrColumnStateCantNone)
-	c.Assert(int(terror.ToSQLError(ErrColumnStateNonPublic).Code), Equals, mysql.ErrColumnStateNonPublic)
-	c.Assert(int(terror.ToSQLError(ErrIndexStateCantNone).Code), Equals, mysql.ErrIndexStateCantNone)
-	c.Assert(int(terror.ToSQLError(ErrInvalidRecordKey).Code), Equals, mysql.ErrInvalidRecordKey)
-	c.Assert(int(terror.ToSQLError(ErrTruncatedWrongValueForField).Code), Equals, mysql.ErrTruncatedWrongValueForField)
-	c.Assert(int(terror.ToSQLError(ErrUnknownPartition).Code), Equals, mysql.ErrUnknownPartition)
-	c.Assert(int(terror.ToSQLError(ErrNoPartitionForGivenValue).Code), Equals, mysql.ErrNoPartitionForGivenValue)
-	c.Assert(int(terror.ToSQLError(ErrLockOrActiveTransaction).Code), Equals, mysql.ErrLockOrActiveTransaction)
+	c.Assert(int(ErrColumnCantNull.ToSQLError().Code), Equals, mysql.ErrBadNull)
+	c.Assert(int(ErrUnknownColumn.ToSQLError().Code), Equals, mysql.ErrBadField)
+	c.Assert(int(errDuplicateColumn.ToSQLError().Code), Equals, mysql.ErrFieldSpecifiedTwice)
+	c.Assert(int(errGetDefaultFailed.ToSQLError().Code), Equals, mysql.ErrFieldGetDefaultFailed)
+	c.Assert(int(ErrNoDefaultValue.ToSQLError().Code), Equals, mysql.ErrNoDefaultForField)
+	c.Assert(int(ErrIndexOutBound.ToSQLError().Code), Equals, mysql.ErrIndexOutBound)
+	c.Assert(int(ErrUnsupportedOp.ToSQLError().Code), Equals, mysql.ErrUnsupportedOp)
+	c.Assert(int(ErrRowNotFound.ToSQLError().Code), Equals, mysql.ErrRowNotFound)
+	c.Assert(int(ErrTableStateCantNone.ToSQLError().Code), Equals, mysql.ErrTableStateCantNone)
+	c.Assert(int(ErrColumnStateCantNone.ToSQLError().Code), Equals, mysql.ErrColumnStateCantNone)
+	c.Assert(int(ErrColumnStateNonPublic.ToSQLError().Code), Equals, mysql.ErrColumnStateNonPublic)
+	c.Assert(int(ErrIndexStateCantNone.ToSQLError().Code), Equals, mysql.ErrIndexStateCantNone)
+	c.Assert(int(ErrInvalidRecordKey.ToSQLError().Code), Equals, mysql.ErrInvalidRecordKey)
+	c.Assert(int(ErrTruncatedWrongValueForField.ToSQLError().Code), Equals, mysql.ErrTruncatedWrongValueForField)
+	c.Assert(int(ErrUnknownPartition.ToSQLError().Code), Equals, mysql.ErrUnknownPartition)
+	c.Assert(int(ErrNoPartitionForGivenValue.ToSQLError().Code), Equals, mysql.ErrNoPartitionForGivenValue)
+	c.Assert(int(ErrLockOrActiveTransaction.ToSQLError().Code), Equals, mysql.ErrLockOrActiveTransaction)
 }
diff --git a/tablecodec/tablecodec_test.go b/tablecodec/tablecodec_test.go
index b56c3cd6b9901..74ad57e626f60 100644
--- a/tablecodec/tablecodec_test.go
+++ b/tablecodec/tablecodec_test.go
@@ -528,7 +528,7 @@ func (s *testTableCodecSuite) TestError(c *C) {
 		errInvalidIndexKey,
 	}
 	for _, err := range kvErrs {
-		code := terror.ToSQLError(err).Code
+		code := err.ToSQLError().Code
 		c.Assert(code != mysql.ErrUnknown && code == uint16(err.Code()), IsTrue, Commentf("err: %v", err))
 	}
 }
diff --git a/types/errors_test.go b/types/errors_test.go
index 56aa43bfc9b98..6f7c92b613f3b 100644
--- a/types/errors_test.go
+++ b/types/errors_test.go
@@ -51,7 +51,7 @@ func (s testErrorSuite) TestError(c *C) {
 		ErrWrongValue,
 	}
 	for _, err := range kvErrs {
-		code := terror.ToSQLError(err).Code
+		code := err.ToSQLError().Code
 		c.Assert(code != mysql.ErrUnknown && code == uint16(err.Code()), IsTrue, Commentf("err: %v", err))
 	}
 }
diff --git a/util/admin/admin_test.go b/util/admin/admin_test.go
index 235efbd99d829..28a6a8206fa93 100644
--- a/util/admin/admin_test.go
+++ b/util/admin/admin_test.go
@@ -382,7 +382,7 @@ func (s *testSuite) TestError(c *C) {
 		ErrCannotCancelDDLJob,
 	}
 	for _, err := range kvErrs {
-		code := terror.ToSQLError(err).Code
+		code := err.ToSQLError().Code
 		c.Assert(code != mysql.ErrUnknown && code == uint16(err.Code()), IsTrue, Commentf("err: %v", err))
 	}
 }
diff --git a/util/memory/tracker_test.go b/util/memory/tracker_test.go
index f9f498cfee1ee..c6b4191595c77 100644
--- a/util/memory/tracker_test.go
+++ b/util/memory/tracker_test.go
@@ -21,7 +21,6 @@ import (
 
 	"github.com/cznic/mathutil"
 	. "github.com/pingcap/check"
-	"github.com/pingcap/parser/terror"
 	"github.com/pingcap/tidb/errno"
 	"github.com/pingcap/tidb/util/logutil"
 	"github.com/pingcap/tidb/util/testleak"
@@ -339,5 +338,5 @@ func BenchmarkConsume(b *testing.B) {
 }
 
 func (s *testSuite) TestErrorCode(c *C) {
-	c.Assert(int(terror.ToSQLError(errMemExceedThreshold).Code), Equals, errno.ErrMemExceedThreshold)
+	c.Assert(int(errMemExceedThreshold.ToSQLError().Code), Equals, errno.ErrMemExceedThreshold)
 }
diff --git a/util/testkit/testkit.go b/util/testkit/testkit.go
index 00f12ced1c832..1ae061c3b0adc 100644
--- a/util/testkit/testkit.go
+++ b/util/testkit/testkit.go
@@ -279,7 +279,7 @@ func (tk *TestKit) MustGetErrCode(sql string, errCode int) {
 	originErr := errors.Cause(err)
 	tErr, ok := originErr.(*terror.Error)
 	tk.c.Assert(ok, check.IsTrue, check.Commentf("expect type 'terror.Error', but obtain '%T'", originErr))
-	sqlErr := terror.ToSQLError(tErr)
+	sqlErr := tErr.ToSQLError()
 	tk.c.Assert(int(sqlErr.Code), check.Equals, errCode, check.Commentf("Assertion failed, origin err:\n  %v", sqlErr))
 }