SQLStore: Fix wrong usage of xorm's insert functions in tests (#63850)

* SQLStore: Fix InsertId

* Prefs: Fix Insert return value

* Fix tests

* Add guidelines

pkg/services/sqlstore/session.go

@@ -126,21 +126,21 @@ func (ss *SQLStore) withDbSession(ctx context.Context, engine *xorm.Engine, call
 	return retryer.Retry(ss.retryOnLocks(ctx, callback, sess, retry), ss.dbCfg.QueryRetries, time.Millisecond*time.Duration(10), time.Second)
 }
 
-func (sess *DBSession) InsertId(bean interface{}, dialect migrator.Dialect) (int64, error) {
+func (sess *DBSession) InsertId(bean interface{}, dialect migrator.Dialect) error {
 	table := sess.DB().Mapper.Obj2Table(getTypeName(bean))
 
 	if err := dialect.PreInsertId(table, sess.Session); err != nil {
-		return 0, err
+		return err
 	}
-	id, err := sess.Session.InsertOne(bean)
+	_, err := sess.Session.InsertOne(bean)
 	if err != nil {
-		return 0, err
+		return err
 	}
 	if err := dialect.PostInsertId(table, sess.Session); err != nil {
-		return 0, err
+		return err
 	}
 
-	return id, nil
+	return nil
 }
 
 func (sess *DBSession) WithReturningID(driverName string, query string, args []interface{}) (int64, error) {

pkg/services/sqlstore/user.go

@@ -172,7 +172,7 @@ func (ss *SQLStore) getOrCreateOrg(sess *DBSession, orgName string) (int64, erro
 	org.Updated = time.Now()
 
 	if org.ID != 0 {
-		if _, err := sess.InsertId(&org, ss.Dialect); err != nil {
+		if err := sess.InsertId(&org, ss.Dialect); err != nil {
 			return 0, err
 		}
 	} else {