diff options
| -rw-r--r-- | lib/schema.php | 309 |
1 files changed, 272 insertions, 37 deletions
diff --git a/lib/schema.php b/lib/schema.php index 8c8f5e9ff..1e0c1f3e9 100644 --- a/lib/schema.php +++ b/lib/schema.php @@ -50,15 +50,29 @@ class Schema 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::$_single)) { @@ -67,6 +81,17 @@ class Schema return self::$_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); @@ -108,6 +133,18 @@ class Schema 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); @@ -121,12 +158,17 @@ class Schema 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(); @@ -145,13 +187,13 @@ class Schema $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; } @@ -171,8 +213,6 @@ class Schema $sql .= "); "; - common_debug($sql); - $res =& $this->conn->query($sql); if (PEAR::isError($res)) { @@ -182,6 +222,16 @@ class Schema 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 $name"); @@ -193,7 +243,23 @@ class Schema return true; } - public function createIndex($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); @@ -203,7 +269,9 @@ class Schema $name = "$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()); @@ -212,6 +280,15 @@ class Schema 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"); @@ -223,6 +300,16 @@ class Schema 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); @@ -236,9 +323,21 @@ class Schema 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); @@ -249,6 +348,17 @@ class Schema 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 $columnName"; @@ -262,7 +372,22 @@ class Schema return true; } - public function ensureTable($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 @@ -270,7 +395,7 @@ class Schema $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; } @@ -281,10 +406,8 @@ class Schema $toadd = array_diff($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, $m); @@ -307,6 +430,7 @@ class Schema foreach ($toadd as $columnName) { $cd = $this->_byName($columns, $columnName); + $phrase[] = 'ADD COLUMN ' . $this->_columnSql($cd); } @@ -316,6 +440,7 @@ class Schema foreach ($tomod as $columnName) { $cd = $this->_byName($columns, $columnName); + $phrase[] = 'MODIFY COLUMN ' . $this->_columnSql($cd); } @@ -330,7 +455,16 @@ class Schema 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(); @@ -341,7 +475,17 @@ class Schema 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 == $name) { @@ -352,7 +496,19 @@ class Schema return null; } - function _columnSql($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} "; @@ -372,25 +528,71 @@ class Schema } } +/** + * 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; @@ -400,6 +602,15 @@ class ColumnDef $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 && @@ -409,37 +620,61 @@ class ColumnDef $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; -} |