/**
*
* Alter columns and indexes of a table based on DB_Table column and index
* arrays.
*
* @static
*
* @access public
*
* @param object &$db A PEAR DB/MDB2 object.
*
* @param string $table The table name to connect to in the database.
*
* @param mixed $column_set A DB_Table $this->col array.
*
* @param mixed $index_set A DB_Table $this->idx array.
*
* @return bool|object True if altering was successful or a PEAR_Error on
* failure.
*
*/
function alter(&$db, $table, $column_set, $index_set)
{
list($phptype, ) = DB_Table::getPHPTypeAndDBSyntax($db);
if (is_subclass_of($db, 'db_common')) {
$backend = 'db';
$reverse =& $db;
// workaround for missing index and constraint information methods
// in PEAR::DB ==> use adopted code from MDB2's driver classes
require_once 'DB/Table/Manager/' . $phptype . '.php';
$classname = 'DB_Table_Manager_' . $phptype;
$dbtm =& new $classname();
$dbtm->_db =& $db;
// pass database instance to the 'workaround' class
$manager =& $dbtm;
$table_info_mode = DB_TABLEINFO_FULL;
$ok_const = DB_OK;
} elseif (is_subclass_of($db, 'mdb2_driver_common')) {
$backend = 'mdb2';
$db->loadModule('Reverse');
$manager =& $db->manager;
$reverse =& $db->reverse;
$table_info_mode = MDB2_TABLEINFO_FULL;
$ok_const = MDB2_OK;
}
// get table info
$tableInfo = $reverse->tableInfo($table, $table_info_mode);
if (PEAR::isError($tableInfo)) {
return $tableInfo;
}
$tableInfoOrder = array_change_key_case($tableInfo['order'], CASE_LOWER);
// emulate MDB2 Reverse extension for PEAR::DB as backend
if (is_subclass_of($db, 'db_common')) {
$reverse =& $dbtm;
}
// check (and alter) columns
if (is_null($column_set)) {
$column_set = array();
}
foreach ($column_set as $colname => $val) {
$colname = strtolower(trim($colname));
// check the column name
$name_check = DB_Table_Manager::_validateColumnName($colname);
if (PEAR::isError($name_check)) {
return $name_check;
}
// check the column's existence
$column_exists = DB_Table_Manager::_columnExists($colname, $tableInfoOrder, 'alter');
if (PEAR::isError($column_exists)) {
return $column_exists;
}
if ($column_exists === false) {
// add the column
$definition = DB_Table_Manager::_getColumnDefinition($backend, $phptype, $val);
if (PEAR::isError($definition)) {
return $definition;
}
$changes = array('add' => array($colname => $definition));
if (array_key_exists('debug', $GLOBALS['_DB_TABLE'])) {
echo "(alter) New table field will be added ({$colname}):\n";
var_dump($changes);
echo "\n";
}
$result = $manager->alterTable($table, $changes, false);
if (PEAR::isError($result)) {
return $result;
}
continue;
}
// check whether the column type is a known type
$type_check = DB_Table_Manager::_validateColumnType($phptype, $val['type']);
if (PEAR::isError($type_check)) {
return $type_check;
}
// check whether the column has the right type
$type_check = DB_Table_Manager::_checkColumnType($phptype, $colname, $val['type'], $tableInfoOrder, $tableInfo, 'alter');
if (PEAR::isError($type_check)) {
return $type_check;
}
if ($type_check === false) {
// change the column type
$definition = DB_Table_Manager::_getColumnDefinition($backend, $phptype, $val);
if (PEAR::isError($definition)) {
return $definition;
}
$changes = array('change' => array($colname => array('type' => null, 'definition' => $definition)));
if (array_key_exists('debug', $GLOBALS['_DB_TABLE'])) {
echo "(alter) Table field's type will be changed ({$colname}):\n";
var_dump($changes);
echo "\n";
}
$result = $manager->alterTable($table, $changes, false);
if (PEAR::isError($result)) {
return $result;
}
continue;
}
}
// get information about indexes / constraints
$table_indexes = DB_Table_Manager::_getIndexes($db, $table);
if (PEAR::isError($table_indexes)) {
return $table_indexes;
}
// check (and alter) indexes / constraints
if (is_null($index_set)) {
$index_set = array();
}
foreach ($index_set as $idxname => $val) {
list($type, $cols) = DB_Table_Manager::_getIndexTypeAndColumns($val, $idxname);
$newIdxName = '';
// check the index definition
$index_check = DB_Table_Manager::_validateIndexName($idxname, $table, $phptype, $type, $cols, $column_set, $newIdxName);
if (PEAR::isError($index_check)) {
return $index_check;
}
// check whether the index has the right type and has all
// specified columns
$index_check = DB_Table_Manager::_checkIndex($idxname, $newIdxName, $type, $cols, $table_indexes, 'alter');
if (PEAR::isError($index_check)) {
return $index_check;
}
if ($index_check === false) {
// (1) drop wrong index/constraint
// (2) add right index/constraint
if ($backend == 'mdb2') {
// save user defined 'idxname_format' option
$idxname_format = $db->getOption('idxname_format');
$db->setOption('idxname_format', '%s');
}
// drop index/constraint only if it exists
foreach (array('normal', 'unique', 'primary') as $idx_type) {
if (array_key_exists(strtolower($newIdxName), $table_indexes[$idx_type])) {
if (array_key_exists('debug', $GLOBALS['_DB_TABLE'])) {
echo "(alter) Index/constraint will be deleted (name: '{$newIdxName}', type: '{$idx_type}').\n";
}
if ($idx_type == 'normal') {
$result = $manager->dropIndex($table, $newIdxName);
} else {
$result = $manager->dropConstraint($table, $newIdxName);
}
if (PEAR::isError($result)) {
if ($backend == 'mdb2') {
// restore user defined 'idxname_format' option
$db->setOption('idxname_format', $idxname_format);
}
return $result;
}
break;
}
}
// prepare index/constraint definition
$indexes = array();
if ($backend == 'mdb2') {
// array with column names as keys
$idx_cols = array();
foreach ($cols as $col) {
$idx_cols[$col] = array();
}
switch ($type) {
case 'primary':
$indexes['primary'][$newIdxName] = array('fields' => $idx_cols, 'primary' => true);
break;
case 'unique':
$indexes['unique'][$newIdxName] = array('fields' => $idx_cols, 'unique' => true);
break;
case 'normal':
$indexes['normal'][$newIdxName] = array('fields' => $idx_cols);
break;
}
} else {
$indexes[] = DB_Table_Manager::getDeclareForIndex($phptype, $type, $newIdxName, $table, $cols);
}
// create index/constraint
if (array_key_exists('debug', $GLOBALS['_DB_TABLE'])) {
echo "(alter) New index/constraint will be created (name: '{$newIdxName}', type: '{$type}'):\n";
var_dump($indexes);
echo "\n";
}
$result = DB_Table_Manager::_createIndexesAndContraints($db, $backend, $table, $indexes);
if ($backend == 'mdb2') {
// restore user defined 'idxname_format' option
$db->setOption('idxname_format', $idxname_format);
}
if (PEAR::isError($result)) {
return $result;
}
continue;
}
}
return true;
}
