Instead of changing the signature of OrderBy just add OrderByWithArgs

Signed-off-by: Andrew Thornton <art27@cantab.net>

engine.go

@@ -1006,10 +1006,17 @@ func (engine *Engine) Asc(colNames ...string) *Session {
 }
 
 // OrderBy will generate "ORDER BY order"
-func (engine *Engine) OrderBy(order interface{}, args ...interface{}) *Session {
+func (engine *Engine) OrderBy(order string) *Session {
 	session := engine.NewSession()
 	session.isAutoClose = true
-	return session.OrderBy(order, args...)
+	return session.OrderBy(order)
+}
+
+// OrderByWithArgs will generate "ORDER BY order"
+func (engine *Engine) OrderByWithArgs(order interface{}, args ...interface{}) *Session {
+	session := engine.NewSession()
+	session.isAutoClose = true
+	return session.OrderByWithArgs(order, args...)
 }
 
 // Prepare enables prepare statement

interface.go

@@ -54,7 +54,8 @@ type Interface interface {
 	Nullable(...string) *Session
 	Join(joinOperator string, tablename interface{}, condition string, args ...interface{}) *Session
 	Omit(columns ...string) *Session
-	OrderBy(order interface{}, args ...interface{}) *Session
+	OrderBy(order string) *Session
+	OrderByWithArgs(order interface{}, args ...interface{}) *Session
 	Ping() error
 	Query(sqlOrArgs ...interface{}) (resultsSlice []map[string][]byte, err error)
 	QueryInterface(sqlOrArgs ...interface{}) ([]map[string]interface{}, error)

internal/statements/statement.go

@@ -457,7 +457,12 @@ func (statement *Statement) Limit(limit int, start ...int) *Statement {
 }
 
 // OrderBy generate "Order By order" statement
-func (statement *Statement) OrderBy(order interface{}, args ...interface{}) *Statement {
+func (statement *Statement) OrderBy(order string) *Statement {
+	return statement.OrderByWithArgs(order)
+}
+
+// OrderByWithArgs generate "Order By order" statement
+func (statement *Statement) OrderByWithArgs(order interface{}, args ...interface{}) *Statement {
 	var rawOrder string
 	switch order.(type) {
 	case (*builder.Builder):

session.go

@@ -275,8 +275,15 @@ func (session *Session) Limit(limit int, start ...int) *Session {
 
 // OrderBy provide order by query condition, the input parameter is the content
 // after order by on a sql statement.
-func (session *Session) OrderBy(order interface{}, args ...interface{}) *Session {
-	session.statement.OrderBy(order, args...)
+func (session *Session) OrderBy(order string) *Session {
+	session.statement.OrderBy(order)
+	return session
+}
+
+// OrderByWithArgs provide order by query condition, the input parameter is the content
+// after order by on a sql statement.
+func (session *Session) OrderByWithArgs(order interface{}, args ...interface{}) *Session {
+	session.statement.OrderByWithArgs(order, args...)
 	return session
 }