function db_add_field

Add a new field to a table.

Parameters

$ret: Array to which query results will be added.

$table: Name of the table to be altered.

$field: Name of the field to be added.

$spec: The field specification array, as taken from a schema definition. The specification may also contain the key 'initial', the newly created field will be set to the value of the key in all rows. This is most useful for creating NOT NULL columns with no default value in existing tables.

$keys_new: (optional) Keys and indexes specification to be created on the table along with adding the field. The format is the same as a table specification but without the 'fields' element. If you are adding a type 'serial' field, you MUST specify at least one key or index including it in this array. See db_change_field() for more explanation why.

Related topics

File

includes/database.mysql-common.inc, line 296

Functions shared between mysql and mysqli database engines.

Code

function db_add_field(&$ret, $table, $field, $spec, $keys_new = array()) {
  $fixnull = FALSE;
  if (!empty($spec['not null']) && !isset($spec['default'])) {
    $fixnull = TRUE;
    $spec['not null'] = FALSE;
  }
  $query = 'ALTER TABLE {' . $table . '} ADD ';
  $query .= _db_create_field_sql($field, _db_process_field($spec));
  if (count($keys_new)) {
    $query .= ', ADD ' . implode(', ADD ', _db_create_keys_sql($keys_new));
  }
  $ret[] = update_sql($query);
  if (isset($spec['initial'])) {

    // All this because update_sql does not support %-placeholders.
    $sql = 'UPDATE {' . $table . '} SET ' . $field . ' = ' . db_type_placeholder($spec['type']);
    $result = db_query($sql, $spec['initial']);
    $ret[] = array(
      'success' => $result !== FALSE,
      'query' => check_plain($sql . ' (' . $spec['initial'] . ')'),
    );
  }
  if ($fixnull) {
    $spec['not null'] = TRUE;
    db_change_field($ret, $table, $field, $field, $spec);
  }
}