isUniqueSQLField static method

ValidatorEvent isUniqueSQLField({ required MySQLConnection db, required String table, required String field, QO operator = QO.EQ, Where? where, })

Validator to check if a field value is unique in a SQL database table. The validator checks whether the provided value already exists in the specified table and field. If the value exists, an error message 'error.field.unique' is returned. Parameters:

• db: The MySQLConnection instance to use for the database query. (required)
• table: The name of the database table to check. (required)
• field: The name of the field/column to check for uniqueness. (required)
• operator: The comparison operator to use in the query. Defaults to QO.EQ.
• where: An optional additional Where clause to further filter the query. Returns:
• ValidatorEvent: A validator event function that can be used in the FormValidator.

Implementation

static ValidatorEvent isUniqueSQLField({
  required MySQLConnection db,
  required String table,
  required String field,
  QO operator = QO.EQ,
  Where? where,
}) {
  return (v) async {
    Sqler sqler = Sqler();
    sqler.from(QField(table));
    sqler.addSelect(SQL.count(QField(field, as: 'count_of_field')));
    sqler.where(WhereOne(QField(field), operator, QVar(v)));
    if (where != null) {
      sqler.where(where);
    }
    var res = await db.execute(sqler.toSQL());
    if (res.rows.isNotEmpty) {
      var count = res.rows.first.assoc()['count_of_field'] ?? '0';
      if (count.toString().toInt(def: 10) == 0) {
        return FieldValidateResult(success: true);
      }
    }

    return FieldValidateResult(success: false, error: 'error.field.unique');
  };
}