db_add_column

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Definition

db_add_column(&$ret, $table, $column, $type, $attributes = array())
update.php, line 50

Description

Add a column to a database using syntax appropriate for PostgreSQL. Save result of SQL commands in $ret array.

Note: when you add a column with NOT NULL and you are not sure if there are already rows in the table, you MUST also add DEFAULT. Otherwise PostgreSQL won't work when the table is not empty, and db_add_column() will fail. To have an empty string as the default, you must use: 'default' => "''" in the $attributes array. If NOT NULL and DEFAULT are set the PostgreSQL version will set values of the added column in old rows to the DEFAULT value.

Parameters

$ret Array to which results will be added.

$table Name of the table, without {}

$column Name of the column

$type Type of column

$attributes Additional optional attributes. Recognized attributes: not null => TRUE|FALSE default => NULL|FALSE|value (the value must be enclosed in '' marks)

Return value

nothing, but modifies $ret parameter.

Code

<?php
function db_add_column(&$ret, $table, $column, $type, $attributes = array()) {
  if (array_key_exists('not null', $attributes) and $attributes['not null']) {
    $not_null = 'NOT NULL';
  }
  if (array_key_exists('default', $attributes)) {
    if (is_null($attributes['default'])) {
      $default_val = 'NULL';
      $default = 'default NULL';
    }
    elseif ($attributes['default'] === FALSE) {
      $default = '';
    }
    else {
      $default_val = "$attributes[default]";
      $default = "default $attributes[default]";
    }
  }

  $ret[] = update_sql("ALTER TABLE {". $table ."} ADD $column $type");
  if (!empty($default)) {
    $ret[] = update_sql("ALTER TABLE {". $table ."} ALTER $column SET $default");
  }
  if (!empty($not_null)) {
    if (!empty($default)) {
      $ret[] = update_sql("UPDATE {". $table ."} SET $column = $default_val");
    }
    $ret[] = update_sql("ALTER TABLE {". $table ."} ALTER $column SET NOT NULL");
  }
}
?>