fix

Author: demoManito

migrator/migrator.go

@@ -123,7 +123,6 @@ func (m Migrator) AutoMigrate(values ...interface{}) error {
 					parseCheckConstraints = stmt.Schema.ParseCheckConstraints()
 				)
 				for _, dbName := range stmt.Schema.DBNames {
-					field := stmt.Schema.FieldsByDBName[dbName]
 					var foundColumn gorm.ColumnType
 
 					for _, columnType := range columnTypes {
@@ -140,6 +139,7 @@ func (m Migrator) AutoMigrate(values ...interface{}) error {
 						}
 					} else {
 						// found, smartly migrate
+						field := stmt.Schema.FieldsByDBName[dbName]
 						if err = execTx.Migrator().MigrateColumn(value, field, foundColumn); err != nil {
 							return err
 						}