/**
* get declaration of a field
*
* @param string $field_name name of the field to be created
* @param string $field associative array with the name of the properties
* of the field being declared as array indexes. Currently, the types
* of supported field properties are as follows:
*
* default
* Boolean value to be used as default for this field.
*
* notnull
* Boolean flag that indicates whether this field is constrained
* to not be set to NULL.
* @return mixed string on success, a MDB error on failure
* @access public
*/
function getFieldDeclaration($field_name, $field)
{
$result = $this->loadManager('Get table field definition');
if (MDB::isError($result)) {
return $result;
}
return $this->manager->getFieldDeclaration($this, $field_name, $field);
}
/**
* alter an existing table
*
* @param object $db database object that is extended by this class
* @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.
*
* AddedFields
*
* 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.
*
* Additionally, there should be an 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.
*
* RemovedFields
*
* 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.
*
* RenamedFields
*
* 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.
*
* ChangedFields
*
* 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 ChangedFields 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.
*
* If the default property is meant to be added, removed or changed, there
* should also be an entry with index ChangedDefault assigned to 1. Similarly,
* if the notnull constraint is to be added or removed, there should also be
* an entry with index ChangedNotNull assigned to 1.
*
* Additionally, there should be an entry named Declaration that is expected
* to contain the portion of the field changed declaration already in DBMS
* specific SQL code as it is used in the CREATE TABLE statement.
* Example
* array(
* 'name' => 'userlist',
* 'AddedFields' => array(
* 'quota' => array(
* 'type' => 'integer',
* 'unsigned' => 1
* 'Declaration' => 'quota INT'
* )
* ),
* 'RemovedFields' => array(
* 'file_limit' => array(),
* 'time_limit' => array()
* ),
* 'ChangedFields' => array(
* 'gender' => array(
* 'default' => 'M',
* 'ChangeDefault' => 1,
* 'Declaration' => "gender CHAR(1) DEFAULT 'M'"
* )
* ),
* 'RenamedFields' => array(
* 'sex' => array(
* 'name' => 'gender',
* 'Declaration' => "gender CHAR(1) DEFAULT 'M'"
* )
* )
* )
* @param boolean $check indicates whether the function should just check if the DBMS driver
* can perform the requested table alterations if the value is TRUE or
* actually perform them otherwise.
* @return mixed MDB_OK on success, a MDB error on failure
* @access public
**/
function alterTable(&$db, $name, &$changes, $check)
{
if ($check) {
for ($change = 0, reset($changes); $change < count($changes); next($changes), $change++) {
switch (key($changes)) {
case "AddedFields":
case "RemovedFields":
case "RenamedFields":
break;
case "ChangedFields":
$fields = $changes['ChangedFields'];
for ($field = 0, reset($fields); $field < count($fields); next($fields), $field++) {
if (MDB::isError($err = $this->checkSupportedChanges($fields[Key($fields)]))) {
return $err;
}
}
break;
default:
return $this->raiseError(MDB_ERROR_MANAGER, NULL, NULL, 'Alter table: change type ' . key($changes) . ' not yet supported');
}
}
return MDB_OK;
} else {
$query = '';
if (isset($changes['AddedFields'])) {
$fields = $changes['AddedFields'];
for ($field = 0, reset($fields); $field < count($fields); next($fields), $field++) {
if (strcmp($query, "")) {
$query .= ', ';
}
$query .= 'ADD ' . $fields[key($fields)]['Declaration'];
}
}
if (isset($changes['RemovedFields'])) {
$fields = $changes['RemovedFields'];
for ($field = 0, reset($fields); $field < count($fields); next($fields), $field++) {
if (strcmp($query, "")) {
$query .= ', ';
}
$query .= 'DROP ' . key($fields);
}
}
if (isset($changes['RenamedFields'])) {
$fields = $changes['RenamedFields'];
for ($field = 0, reset($fields); $field < count($fields); next($fields), $field++) {
if (strcmp($query, "")) {
$query .= ', ';
}
$query .= 'ALTER ' . key($fields) . ' TO ' . $fields[Key($fields)]['name'];
}
}
if (isset($changes['ChangedFields'])) {
$fields = $changes['ChangedFields'];
for ($field = 0, reset($fields); $field < count($fields); next($fields), $field++) {
$field_name = key($fields);
if (MDB::isError($err = $this->CheckSupportedChanges($fields[Key($fields)]))) {
return $err;
}
if (strcmp($query, "")) {
$query .= ', ';
}
$query .= 'ALTER ' . $field_name . ' TYPE ' . $db->getFieldDeclaration($fields[$field_name]['Definition']);
}
}
if (MDB::isError($err = $db->query("ALTER TABLE {$name} {$query}"))) {
return $err;
}
return MDB_OK;
}
}
