diff --git a/association.go b/association.go
index 8c6d9864..e9b170f4 100644
--- a/association.go
+++ b/association.go
@@ -367,6 +367,7 @@ func (association *Association) saveAssociations(values ...interface{}) *Associa
 	return association
 }
 
+// seterr set error when the error is not nil. And return Association.
 func (association *Association) setErr(err error) *Association {
 	if err != nil {
 		association.Error = err