func (b *Backend) AlterField(db *sql.DB, m driver.Model, table *sql.Table, oldField *sql.Field, newField *sql.Field) error {
fsql, cons, err := newField.SQL(db, m, table)
if err != nil {
return err
}
tableName := db.QuoteIdentifier(m.Table())
if _, err = db.Exec(fmt.Sprintf("ALTER TABLE %s CHANGE COLUMN %s %s", tableName, db.QuoteIdentifier(oldField.Name), fsql)); err != nil {
return err
}
for _, c := range cons {
if _, err = db.Exec(fmt.Sprintf("ALTER TABLE %s ADD CONSTRAINT %s", tableName, c)); err != nil {
return err
}
}
return err
}
