diff --git a/pkg/util/xorm/interface.go b/pkg/util/xorm/interface.go
index 9bde13a391e..4ef7fb033bc 100644
--- a/pkg/util/xorm/interface.go
+++ b/pkg/util/xorm/interface.go
@@ -14,64 +14,64 @@ import (
 
 // Interface defines the interface which Engine and Session will implementate.
 type Interface interface {
-	AllCols() *Session
-	Alias(alias string) *Session
-	Asc(colNames ...string) *Session
-	BufferSize(size int) *Session
-	Cols(columns ...string) *Session
+	AllCols() Interface
+	Alias(alias string) Interface
+	Asc(colNames ...string) Interface
+	BufferSize(size int) Interface
+	Cols(columns ...string) Interface
 	Count(...interface{}) (int64, error)
 	CreateIndexes(bean interface{}) error
 	CreateUniques(bean interface{}) error
-	Decr(column string, arg ...interface{}) *Session
-	Desc(...string) *Session
+	Decr(column string, arg ...interface{}) Interface
+	Desc(...string) Interface
 	Delete(interface{}) (int64, error)
-	Distinct(columns ...string) *Session
+	Distinct(columns ...string) Interface
 	DropIndexes(bean interface{}) error
 	Exec(sqlOrArgs ...interface{}) (sql.Result, error)
 	Exist(bean ...interface{}) (bool, error)
 	Find(interface{}, ...interface{}) error
 	FindAndCount(interface{}, ...interface{}) (int64, error)
 	Get(interface{}) (bool, error)
-	GroupBy(keys string) *Session
-	ID(interface{}) *Session
-	In(string, ...interface{}) *Session
-	Incr(column string, arg ...interface{}) *Session
+	GroupBy(keys string) Interface
+	ID(interface{}) Interface
+	In(string, ...interface{}) Interface
+	Incr(column string, arg ...interface{}) Interface
 	Insert(...interface{}) (int64, error)
 	InsertOne(interface{}) (int64, error)
 	IsTableEmpty(bean interface{}) (bool, error)
 	IsTableExist(beanOrTableName interface{}) (bool, error)
 	Iterate(interface{}, IterFunc) error
-	Limit(int, ...int) *Session
-	MustCols(columns ...string) *Session
-	NoAutoCondition(...bool) *Session
-	NotIn(string, ...interface{}) *Session
+	Limit(int, ...int) Interface
+	MustCols(columns ...string) Interface
+	NoAutoCondition(...bool) Interface
+	NotIn(string, ...interface{}) Interface
 	Join(joinOperator string, tablename interface{}, condition string, args ...interface{}) *Session
-	Omit(columns ...string) *Session
-	OrderBy(order string) *Session
+	Omit(columns ...string) Interface
+	OrderBy(order string) Interface
 	Ping() error
 	Query(sqlOrArgs ...interface{}) (resultsSlice []map[string][]byte, err error)
 	QueryInterface(sqlOrArgs ...interface{}) ([]map[string]interface{}, error)
 	QueryString(sqlOrArgs ...interface{}) ([]map[string]string, error)
 	Rows(bean interface{}) (*Rows, error)
-	SetExpr(string, interface{}) *Session
-	SQL(interface{}, ...interface{}) *Session
+	SetExpr(string, interface{}) Interface
+	SQL(interface{}, ...interface{}) Interface
 	Sum(bean interface{}, colName string) (float64, error)
 	SumInt(bean interface{}, colName string) (int64, error)
 	Sums(bean interface{}, colNames ...string) ([]float64, error)
 	SumsInt(bean interface{}, colNames ...string) ([]int64, error)
-	Table(tableNameOrBean interface{}) *Session
-	Unscoped() *Session
+	Table(tableNameOrBean interface{}) Interface
+	Unscoped() Interface
 	Update(bean interface{}, condiBeans ...interface{}) (int64, error)
-	UseBool(...string) *Session
-	Where(interface{}, ...interface{}) *Session
+	UseBool(...string) Interface
+	Where(interface{}, ...interface{}) Interface
 }
 
 // EngineInterface defines the interface which Engine will implementate.
 type EngineInterface interface {
 	Interface
 
-	Before(func(interface{})) *Session
-	Charset(charset string) *Session
+	Before(func(interface{})) Interface
+	Charset(charset string) Interface
 	CreateTables(...interface{}) error
 	DBMetas() ([]*core.Table, error)
 	Dialect() core.Dialect
@@ -80,8 +80,8 @@ type EngineInterface interface {
 	GetTableMapper() core.IMapper
 	GetTZDatabase() *time.Location
 	GetTZLocation() *time.Location
-	NewSession() *Session
-	NoAutoTime() *Session
+	NewSession() Interface
+	NoAutoTime() Interface
 	Quote(string) string
 	SetConnMaxLifetime(time.Duration)
 	SetColumnMapper(core.IMapper)
@@ -97,12 +97,7 @@ type EngineInterface interface {
 	ShowSQL(show ...bool)
 	Sync(...interface{}) error
 	Sync2(...interface{}) error
-	StoreEngine(storeEngine string) *Session
+	StoreEngine(storeEngine string) Interface
 	TableName(interface{}, ...bool) string
 	UnMapType(reflect.Type)
 }
-
-var (
-	_ Interface       = &Session{}
-	_ EngineInterface = &Engine{}
-)