static $_single = null;
protected $conn = null;
+ /**
+ * Constructor. Only run once for singleton object.
+ */
+
protected function __construct()
{
// XXX: there should be an easier way to do this.
$user = new User();
+
$this->conn = $user->getDatabaseConnection();
+
$user->free();
+
unset($user);
}
+ /**
+ * Main public entry point. Use this to get
+ * the singleton object.
+ *
+ * @return Schema the (single) Schema object
+ */
+
static function get()
{
if (empty(self::$_single)) {
return self::$_single;
}
+ /**
+ * Returns a TableDef object for the table
+ * in the schema with the given name.
+ *
+ * Throws an exception if the table is not found.
+ *
+ * @param string $name Name of the table to get
+ *
+ * @return TableDef tabledef for that table.
+ */
+
public function getTableDef($name)
{
$res =& $this->conn->query('DESCRIBE ' . $name);
return $td;
}
+ /**
+ * Gets a ColumnDef object for a single column.
+ *
+ * Throws an exception if the table is not found.
+ *
+ * @param string $table name of the table
+ * @param string $column name of the column
+ *
+ * @return ColumnDef definition of the column or null
+ * if not found.
+ */
+
public function getColumnDef($table, $column)
{
$td = $this->getTableDef($table);
return null;
}
- public function getIndexDef($table, $index)
- {
- return null;
- }
-
- public function createTable($name, $columns, $indices=null)
+ /**
+ * Creates a table with the given names and columns.
+ *
+ * @param string $name Name of the table
+ * @param array $columns Array of ColumnDef objects
+ * for new table.
+ *
+ * @return boolean success flag
+ */
+
+ public function createTable($name, $columns)
{
$uniques = array();
$primary = array();
$sql .= $this->_columnSql($cd);
switch ($cd->key) {
- case 'UNI':
+ case 'UNI':
$uniques[] = $cd->name;
break;
- case 'PRI':
+ case 'PRI':
$primary[] = $cd->name;
break;
- case 'MUL':
+ case 'MUL':
$indices[] = $cd->name;
break;
}
$sql .= "); ";
- common_debug($sql);
-
$res =& $this->conn->query($sql);
if (PEAR::isError($res)) {
return true;
}
+ /**
+ * Drops a table from the schema
+ *
+ * Throws an exception if the table is not found.
+ *
+ * @param string $name Name of the table to drop
+ *
+ * @return boolean success flag
+ */
+
public function dropTable($name)
{
$res =& $this->conn->query("DROP TABLE $name");
return true;
}
- public function createIndex($table, $columnNames, $name = null)
+ /**
+ * Adds an index to a table.
+ *
+ * If no name is provided, a name will be made up based
+ * on the table name and column names.
+ *
+ * Throws an exception on database error, esp. if the table
+ * does not exist.
+ *
+ * @param string $table Name of the table
+ * @param array $columnNames Name of columns to index
+ * @param string $name (Optional) name of the index
+ *
+ * @return boolean success flag
+ */
+
+ public function createIndex($table, $columnNames, $name=null)
{
if (!is_array($columnNames)) {
$columnNames = array($columnNames);
$name = "$table_".implode("_", $columnNames)."_idx";
}
- $res =& $this->conn->query("ALTER TABLE $table ADD INDEX $name (".implode(",", $columnNames).")");
+ $res =& $this->conn->query("ALTER TABLE $table ".
+ "ADD INDEX $name (".
+ implode(",", $columnNames).")");
if (PEAR::isError($res)) {
throw new Exception($res->getMessage());
return true;
}
+ /**
+ * Drops a named index from a table.
+ *
+ * @param string $table name of the table the index is on.
+ * @param string $name name of the index
+ *
+ * @return boolean success flag
+ */
+
public function dropIndex($table, $name)
{
$res =& $this->conn->query("ALTER TABLE $table DROP INDEX $name");
return true;
}
+ /**
+ * Adds a column to a table
+ *
+ * @param string $table name of the table
+ * @param ColumnDef $columndef Definition of the new
+ * column.
+ *
+ * @return boolean success flag
+ */
+
public function addColumn($table, $columndef)
{
$sql = "ALTER TABLE $table ADD COLUMN " . $this->_columnSql($columndef);
return true;
}
+ /**
+ * Modifies a column in the schema.
+ *
+ * The name must match an existing column and table.
+ *
+ * @param string $table name of the table
+ * @param ColumnDef $columndef new definition of the column.
+ *
+ * @return boolean success flag
+ */
+
public function modifyColumn($table, $columndef)
{
- $sql = "ALTER TABLE $table MODIFY COLUMN " . $this->_columnSql($columndef);
+ $sql = "ALTER TABLE $table MODIFY COLUMN " .
+ $this->_columnSql($columndef);
$res =& $this->conn->query($sql);
return true;
}
+ /**
+ * Drops a column from a table
+ *
+ * The name must match an existing column.
+ *
+ * @param string $table name of the table
+ * @param string $columnName name of the column to drop
+ *
+ * @return boolean success flag
+ */
+
public function dropColumn($table, $columnName)
{
$sql = "ALTER TABLE $table DROP COLUMN $columnName";
return true;
}
- public function ensureTable($tableName, $columns, $indices=null)
+ /**
+ * Ensures that a table exists with the given
+ * name and the given column definitions.
+ *
+ * If the table does not yet exist, it will
+ * create the table. If it does exist, it will
+ * alter the table to match the column definitions.
+ *
+ * @param string $tableName name of the table
+ * @param array $columns array of ColumnDef
+ * objects for the table
+ *
+ * @return boolean success flag
+ */
+
+ public function ensureTable($tableName, $columns)
{
// XXX: DB engine portability -> toilet
$td = $this->getTableDef($tableName);
} catch (Exception $e) {
if (preg_match('/no such table/', $e->getMessage())) {
- return $this->createTable($tableName, $columns, $indices);
+ return $this->createTable($tableName, $columns);
} else {
throw $e;
}
$toadd = array_diff($new, $cur);
$todrop = array_diff($cur, $new);
-
- $same = array_intersect($new, $cur);
-
- $tomod = array();
+ $same = array_intersect($new, $cur);
+ $tomod = array();
foreach ($same as $m) {
$curCol = $this->_byName($td->columns, $m);
foreach ($toadd as $columnName) {
$cd = $this->_byName($columns, $columnName);
+
$phrase[] = 'ADD COLUMN ' . $this->_columnSql($cd);
}
foreach ($tomod as $columnName) {
$cd = $this->_byName($columns, $columnName);
+
$phrase[] = 'MODIFY COLUMN ' . $this->_columnSql($cd);
}
return true;
}
- function _names($cds)
+ /**
+ * Returns the array of names from an array of
+ * ColumnDef objects.
+ *
+ * @param array $cds array of ColumnDef objects
+ *
+ * @return array strings for name values
+ */
+
+ private function _names($cds)
{
$names = array();
return $names;
}
- function _byName($cds, $name)
+ /**
+ * Get a ColumnDef from an array matching
+ * name.
+ *
+ * @param array $cds Array of ColumnDef objects
+ * @param string $name Name of the column
+ *
+ * @return ColumnDef matching item or null if no match.
+ */
+
+ private function _byName($cds, $name)
{
foreach ($cds as $cd) {
if ($cd->name == $name) {
return null;
}
- function _columnSql($cd)
+ /**
+ * Return the proper SQL for creating or
+ * altering a column.
+ *
+ * Appropriate for use in CREATE TABLE or
+ * ALTER TABLE statements.
+ *
+ * @param ColumnDef $cd column to create
+ *
+ * @return string correct SQL for that column
+ */
+
+ private function _columnSql($cd)
{
$sql = "{$cd->name} ";
}
}
+/**
+ * A class encapsulating the structure of a table.
+ *
+ * @category Database
+ * @package StatusNet
+ * @author Evan Prodromou <evan@status.net>
+ * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link http://status.net/
+ */
+
class TableDef
{
+ /** name of the table */
public $name;
+ /** array of ColumnDef objects for the columns. */
public $columns;
}
+/**
+ * A class encapsulating the structure of a column in a table.
+ *
+ * @category Database
+ * @package StatusNet
+ * @author Evan Prodromou <evan@status.net>
+ * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link http://status.net/
+ */
+
class ColumnDef
{
+ /** name of the column. */
public $name;
+ /** type of column, e.g. 'int', 'varchar' */
public $type;
+ /** size of the column. */
public $size;
+ /** boolean flag; can it be null? */
public $nullable;
+ /**
+ * type of key: null = no key; 'PRI' => primary;
+ * 'UNI' => unique key; 'MUL' => multiple values.
+ */
public $key;
+ /** default value if any. */
public $default;
+ /** 'extra' stuff. Returned by MySQL, largely
+ * unused. */
public $extra;
+ /**
+ * Constructor.
+ *
+ * @param string $name name of the column
+ * @param string $type type of the column
+ * @param int $size size of the column
+ * @param boolean $nullable can this be null?
+ * @param string $key type of key
+ * @param value $default default value
+ * @param value $extra unused
+ */
+
function __construct($name=null, $type=null, $size=null,
$nullable=true, $key=null, $default=null,
- $extra=null) {
+ $extra=null)
+ {
$this->name = strtolower($name);
$this->type = strtolower($type);
$this->size = $size+0;
$this->extra = $extra;
}
+ /**
+ * Compares this columndef with another to see
+ * if they're functionally equivalent.
+ *
+ * @param ColumnDef $other column to compare
+ *
+ * @return boolean true if equivalent, otherwise false.
+ */
+
function equals($other)
{
return ($this->name == $other->name &&
$this->key == $other->key);
}
- function _typeMatch($other)
+ /**
+ * Does the type of this column match the
+ * type of the other column?
+ *
+ * Checks the type and size of a column. Tries
+ * to ignore differences between synonymous
+ * data types, like 'integer' and 'int'.
+ *
+ * @param ColumnDef $other other column to check
+ *
+ * @return boolean true if they're about equivalent
+ */
+
+ private function _typeMatch($other)
{
switch ($this->type) {
- case 'integer':
- case 'int':
+ case 'integer':
+ case 'int':
return ($other->type == 'integer' ||
$other->type == 'int');
break;
- default:
+ default:
return ($this->type == $other->type &&
$this->size == $other->size);
}
}
- function _defaultMatch($other)
+ /**
+ * Does the default behaviour of this column match
+ * the other?
+ *
+ * @param ColumnDef $other other column to check
+ *
+ * @return boolean true if defaults are effectively the same.
+ */
+
+ private function _defaultMatch($other)
{
return ((is_null($this->default) && is_null($other->default)) ||
($this->default == $other->default));
}
- function _nullMatch($other)
+ /**
+ * Does the null behaviour of this column match
+ * the other?
+ *
+ * @param ColumnDef $other other column to check
+ *
+ * @return boolean true if these columns 'null' the same.
+ */
+
+ private function _nullMatch($other)
{
return ((!is_null($this->default) && !is_null($other->default) &&
$this->default == $other->default) ||
($this->nullable == $other->nullable));
}
}
-
-class IndexDef
-{
- public $name;
- public $table;
- public $columns;
-}
projects / quix0rs-gnu-social.git / commitdiff