/**
* alter an existing table
*
* @param string $name name of the table that is intended to be changed.
* @param array $changes associative array that contains the details of each type
* of change that is intended to be performed. The types of
* changes that are currently supported are defined as follows:
*
* name
*
* New name for the table.
*
* add
*
* Associative array with the names of fields to be added as
* indexes of the array. The value of each entry of the array
* should be set to another associative array with the properties
* of the fields to be added. The properties of the fields should
* be the same as defined by the Metabase parser.
*
*
* remove
*
* Associative array with the names of fields to be removed as indexes
* of the array. Currently the values assigned to each entry are ignored.
* An empty array should be used for future compatibility.
*
* rename
*
* Associative array with the names of fields to be renamed as indexes
* of the array. The value of each entry of the array should be set to
* another associative array with the entry named name with the new
* field name and the entry named Declaration that is expected to contain
* the portion of the field declaration already in DBMS specific SQL code
* as it is used in the CREATE TABLE statement.
*
* change
*
* Associative array with the names of the fields to be changed as indexes
* of the array. Keep in mind that if it is intended to change either the
* name of a field and any other properties, the change array entries
* should have the new names of the fields as array indexes.
*
* The value of each entry of the array should be set to another associative
* array with the properties of the fields to that are meant to be changed as
* array entries. These entries should be assigned to the new values of the
* respective properties. The properties of the fields should be the same
* as defined by the Metabase parser.
*
* Example
* array(
* 'name' => 'userlist',
* 'add' => array(
* 'quota' => array(
* 'type' => 'integer',
* 'unsigned' => 1
* )
* ),
* 'remove' => array(
* 'file_limit' => array(),
* 'time_limit' => array()
* ),
* 'change' => array(
* 'name' => array(
* 'length' => '20',
* 'definition' => array(
* 'type' => 'text',
* 'length' => 20,
* ),
* )
* ),
* 'rename' => array(
* 'sex' => array(
* 'name' => 'gender',
* 'definition' => array(
* 'type' => 'text',
* 'length' => 1,
* 'default' => 'M',
* ),
* )
* )
* )
*
* @param boolean $check indicates whether the function should just check if the DBMS driver
* can perform the requested table alterations if the value is true or
* actually perform them otherwise.
* @return void
*/
public function alterTable($name, array $changes, $check = false)
{
foreach ($changes as $changeName => $change) {
switch ($changeName) {
case 'add':
break;
case 'remove':
break;
case 'name':
case 'rename':
case 'change':
default:
throw SchemaException::alterTableChangeNotSupported($changeName);
}
}
$query = '';
if (!empty($changes['add']) && is_array($changes['add'])) {
foreach ($changes['add'] as $fieldName => $field) {
if ($query) {
$query .= ', ';
}
$query .= 'ADD ' . $this->getDeclaration($fieldName, $field);
}
}
if (!empty($changes['remove']) && is_array($changes['remove'])) {
foreach ($changes['remove'] as $fieldName => $field) {
if ($query) {
$query .= ', ';
}
$query .= 'DROP COLUMN ' . $fieldName;
}
}
if (!$query) {
return false;
}
return $this->conn->exec('ALTER TABLE ' . $name . ' ' . $query);
}
