All migrations work in sqlite3, mysql and postgres

pkg/services/sqlstore/migrations/user_mig.go

@@ -57,7 +57,7 @@ func addUserMigrations(mg *Migrator) {
 			&Column{Name: "org_id", Type: DB_BigInt, Nullable: false},
 			&Column{Name: "is_admin", Type: DB_Bool, Nullable: false},
 			&Column{Name: "email_verified", Type: DB_Bool, Nullable: true},
-			&Column{Name: "theme", Type: DB_NVarchar, Nullable: true},
+			&Column{Name: "theme", Type: DB_NVarchar, Length: 255, Nullable: true},
 			&Column{Name: "created", Type: DB_DateTime, Nullable: false},
 			&Column{Name: "updated", Type: DB_DateTime, Nullable: false},
 		},

pkg/services/sqlstore/migrator/migrator.go

@@ -125,7 +125,7 @@ func (mg *Migrator) exec(m Migration) error {
 			results, err := sess.Query(sql, args...)
 			if err != nil || len(results) == 0 {
 				log.Info("Migrator: skipping migration id: %v, condition not fulfilled", m.Id())
-				return nil
+				return sess.Rollback()
 			}
 		}