diff options
author | Brenda Wallace <shiny@cpan.org> | 2010-01-30 18:45:10 +1300 |
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committer | Brenda Wallace <shiny@cpan.org> | 2010-01-30 18:45:10 +1300 |
commit | e765a9657b0491c6d4fd6436c9cd489342a465c9 (patch) | |
tree | f9377c54a7d555e9ad56a8bf097f8fea9c221dc3 /lib/schema.mysql.php | |
parent | b68a21d4f77f7d05f12bf85068c2d0d1a0ba3a36 (diff) |
move the schema DDL sql off into seperate files for each db we support
Diffstat (limited to 'lib/schema.mysql.php')
-rw-r--r-- | lib/schema.mysql.php | 537 |
1 files changed, 537 insertions, 0 deletions
diff --git a/lib/schema.mysql.php b/lib/schema.mysql.php new file mode 100644 index 000000000..1f7c3d092 --- /dev/null +++ b/lib/schema.mysql.php @@ -0,0 +1,537 @@ +<?php +/** + * StatusNet, the distributed open-source microblogging tool + * + * Database schema utilities + * + * PHP version 5 + * + * LICENCE: This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * @category Database + * @package StatusNet + * @author Evan Prodromou <evan@status.net> + * @copyright 2009 StatusNet, Inc. + * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0 + * @link http://status.net/ + */ + +if (!defined('STATUSNET')) { + exit(1); +} + +/** + * Class representing the database schema + * + * A class representing the database schema. Can be used to + * manipulate the schema -- especially for plugins and upgrade + * utilities. + * + * @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 MysqlSchema extends 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::$_single)) { + self::$_single = new 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 ' . $name); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + $td = new TableDef(); + + $td->name = $name; + $td->columns = array(); + + $row = array(); + + while ($res->fetchInto($row, DB_FETCHMODE_ASSOC)) { + + $cd = new ColumnDef(); + + $cd->name = $row['Field']; + + $packed = $row['Type']; + + if (preg_match('/^(\w+)\((\d+)\)$/', $packed, $match)) { + $cd->type = $match[1]; + $cd->size = $match[2]; + } else { + $cd->type = $packed; + } + + $cd->nullable = ($row['Null'] == 'YES') ? true : false; + $cd->key = $row['Key']; + $cd->default = $row['Default']; + $cd->extra = $row['Extra']; + + $td->columns[] = $cd; + } + + 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); + + foreach ($td->columns as $cd) { + if ($cd->name == $column) { + return $cd; + } + } + + return 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(); + $indices = array(); + + $sql = "CREATE TABLE $name (\n"; + + for ($i = 0; $i < count($columns); $i++) { + + $cd =& $columns[$i]; + + if ($i > 0) { + $sql .= ",\n"; + } + + $sql .= $this->_columnSql($cd); + + switch ($cd->key) { + case 'UNI': + $uniques[] = $cd->name; + break; + case 'PRI': + $primary[] = $cd->name; + break; + case 'MUL': + $indices[] = $cd->name; + break; + } + } + + if (count($primary) > 0) { // it really should be... + $sql .= ",\nconstraint primary key (" . implode(',', $primary) . ")"; + } + + foreach ($uniques as $u) { + $sql .= ",\nunique index {$name}_{$u}_idx ($u)"; + } + + foreach ($indices as $i) { + $sql .= ",\nindex {$name}_{$i}_idx ($i)"; + } + + $sql .= "); "; + + $res = $this->conn->query($sql); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + 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 $name"); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + return true; + } + + /** + * 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); + } + + if (empty($name)) { + $name = "$table_".implode("_", $columnNames)."_idx"; + } + + $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 $name"); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + 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); + + $res = $this->conn->query($sql); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + 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); + + $res = $this->conn->query($sql); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + 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"; + + $res = $this->conn->query($sql); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + return true; + } + + /** + * 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 + + try { + $td = $this->getTableDef($tableName); + } catch (Exception $e) { + if (preg_match('/no such table/', $e->getMessage())) { + return $this->createTable($tableName, $columns); + } else { + throw $e; + } + } + + $cur = $this->_names($td->columns); + $new = $this->_names($columns); + + $toadd = array_diff($new, $cur); + $todrop = array_diff($cur, $new); + $same = array_intersect($new, $cur); + $tomod = array(); + + foreach ($same as $m) { + $curCol = $this->_byName($td->columns, $m); + $newCol = $this->_byName($columns, $m); + + if (!$newCol->equals($curCol)) { + $tomod[] = $newCol->name; + } + } + + if (count($toadd) + count($todrop) + count($tomod) == 0) { + // nothing to do + return true; + } + + // For efficiency, we want this all in one + // query, instead of using our methods. + + $phrase = array(); + + foreach ($toadd as $columnName) { + $cd = $this->_byName($columns, $columnName); + + $phrase[] = 'ADD COLUMN ' . $this->_columnSql($cd); + } + + foreach ($todrop as $columnName) { + $phrase[] = 'DROP COLUMN ' . $columnName; + } + + foreach ($tomod as $columnName) { + $cd = $this->_byName($columns, $columnName); + + $phrase[] = 'MODIFY COLUMN ' . $this->_columnSql($cd); + } + + $sql = 'ALTER TABLE ' . $tableName . ' ' . implode(', ', $phrase); + + $res = $this->conn->query($sql); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + return true; + } + + /** + * 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) + { + $names = array(); + + foreach ($cds as $cd) { + $names[] = $cd->name; + } + + return $names; + } + + /** + * 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 $cd; + } + } + + return null; + } + + /** + * 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} "; + + if (!empty($cd->size)) { + $sql .= "{$cd->type}({$cd->size}) "; + } else { + $sql .= "{$cd->type} "; + } + + if (!empty($cd->default)) { + $sql .= "default {$cd->default} "; + } else { + $sql .= ($cd->nullable) ? "null " : "not null "; + } + + if (!empty($cd->auto_increment)) { + $sql .= " auto_increment "; + } + + if (!empty($cd->extra)) { + $sql .= "{$cd->extra} "; + } + + return $sql; + } +} |