<?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> * @author Brenda Wallace <shiny@cpan.org> * @author Brion Vibber <brion@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 PgsqlSchema extends Schema { /** * Returns a table definition array for the table * in the schema with the given name. * * Throws an exception if the table is not found. * * @param string $table Name of the table to get * * @return array tabledef for that table. */ public function getTableDef($table) { $def = array(); $hasKeys = false; // Pull column data from INFORMATION_SCHEMA $columns = $this->fetchMetaInfo($table, 'columns', 'ordinal_position'); if (count($columns) == 0) { throw new SchemaTableMissingException("No such table: $table"); } // We'll need to match up fields by ordinal reference $orderedFields = array(); foreach ($columns as $row) { $name = $row['column_name']; $orderedFields[$row['ordinal_position']] = $name; $field = array(); $field['type'] = $row['udt_name']; if ($type == 'char' || $type == 'varchar') { if ($row['character_maximum_length'] !== null) { $field['length'] = intval($row['character_maximum_length']); } } if ($type == 'numeric') { // Other int types may report these values, but they're irrelevant. // Just ignore them! if ($row['numeric_precision'] !== null) { $field['precision'] = intval($row['numeric_precision']); } if ($row['numeric_scale'] !== null) { $field['scale'] = intval($row['numeric_scale']); } } if ($row['is_nullable'] == 'NO') { $field['not null'] = true; } if ($row['column_default'] !== null) { $field['default'] = $row['column_default']; if ($this->isNumericType($type)) { $field['default'] = intval($field['default']); } } $def['fields'][$name] = $field; } // Pulling index info from pg_class & pg_index // This can give us primary & unique key info, but not foreign key constraints // so we exclude them and pick them up later. $indexInfo = $this->getIndexInfo($table); foreach ($indexInfo as $row) { $keyName = $row['key_name']; // Dig the column references out! // // These are inconvenient arrays with partial references to the // pg_att table, but since we've already fetched up the column // info on the current table, we can look those up locally. $cols = array(); $colPositions = explode(' ', $row['indkey']); foreach ($colPositions as $ord) { if ($ord == 0) { $cols[] = 'FUNCTION'; // @fixme } else { $cols[] = $orderedFields[$ord]; } } $def['indexes'][$keyName] = $cols; } // Pull constraint data from INFORMATION_SCHEMA: // Primary key, unique keys, foreign keys $keyColumns = $this->fetchMetaInfo($table, 'key_column_usage', 'constraint_name,ordinal_position'); $keys = array(); foreach ($keyColumns as $row) { $keyName = $row['constraint_name']; $keyCol = $row['column_name']; if (!isset($keys[$keyName])) { $keys[$keyName] = array(); } $keys[$keyName][] = $keyCol; } foreach ($keys as $keyName => $cols) { // name hack -- is this reliable? if ($keyName == "{$table}_pkey") { $def['primary key'] = $cols; } else if (preg_match("/^{$table}_(.*)_fkey$/", $keyName, $matches)) { $fkey = $this->getForeignKeyInfo($table, $keyName); $colMap = array_combine($cols, $fkey['col_names']); $def['foreign keys'][$keyName] = array($fkey['table_name'], $colMap); } else { $def['unique keys'][$keyName] = $cols; } } return $def; } /** * Pull some INFORMATION.SCHEMA data for the given table. * * @param string $table * @return array of arrays */ function fetchMetaInfo($table, $infoTable, $orderBy=null) { $query = "SELECT * FROM information_schema.%s " . "WHERE table_name='%s'"; $sql = sprintf($query, $infoTable, $table); if ($orderBy) { $sql .= ' ORDER BY ' . $orderBy; } return $this->fetchQueryData($sql); } /** * Pull some PG-specific index info * @param string $table * @return array of arrays */ function getIndexInfo($table) { $query = 'SELECT ' . '(SELECT relname FROM pg_class WHERE oid=indexrelid) AS key_name, ' . '* FROM pg_index ' . 'WHERE indrelid=(SELECT oid FROM pg_class WHERE relname=\'%s\') ' . 'AND indisprimary=\'f\' AND indisunique=\'f\' ' . 'ORDER BY indrelid, indexrelid'; $sql = sprintf($query, $table); return $this->fetchQueryData($sql); } /** * Column names from the foreign table can be resolved with a call to getTableColumnNames() * @param <type> $table * @return array array of rows with keys: fkey_name, table_name, table_id, col_names (array of strings) */ function getForeignKeyInfo($table, $constraint_name) { // In a sane world, it'd be easier to query the column names directly. // But it's pretty hard to work with arrays such as col_indexes in direct SQL here. $query = 'SELECT ' . '(SELECT relname FROM pg_class WHERE oid=confrelid) AS table_name, ' . 'confrelid AS table_id, ' . '(SELECT indkey FROM pg_index WHERE indexrelid=conindid) AS col_indexes ' . 'FROM pg_constraint ' . 'WHERE conrelid=(SELECT oid FROM pg_class WHERE relname=\'%s\') ' . 'AND conname=\'%s\' ' . 'AND contype=\'f\''; $sql = sprintf($query, $table, $constraint_name); $data = $this->fetchQueryData($sql); if (count($data) < 1) { throw new Exception("Could not find foreign key " . $constraint_name . " on table " . $table); } $row = $data[0]; return array( 'table_name' => $row['table_name'], 'col_names' => $this->getTableColumnNames($row['table_id'], $row['col_indexes']) ); } /** * * @param int $table_id * @param array $col_indexes * @return array of strings */ function getTableColumnNames($table_id, $col_indexes) { $indexes = array_map('intval', explode(' ', $col_indexes)); $query = 'SELECT attnum AS col_index, attname AS col_name ' . 'FROM pg_attribute where attrelid=%d ' . 'AND attnum IN (%s)'; $sql = sprintf($query, $table_id, implode(',', $indexes)); $data = $this->fetchQueryData($sql); $byId = array(); foreach ($data as $row) { $byId[$row['col_index']] = $row['col_name']; } $out = array(); foreach ($indexes as $id) { $out[] = $byId[$id]; } return $out; } /** * Translate the (mostly) mysql-ish column types into somethings more standard * @param string column type * * @return string postgres happy column type */ private function _columnTypeTranslation($type) { $map = array( 'datetime' => 'timestamp', ); if(!empty($map[$type])) { return $map[$type]; } return $type; } /** * Return the proper SQL for creating or * altering a column. * * Appropriate for use in CREATE TABLE or * ALTER TABLE statements. * * @param array $cd column to create * * @return string correct SQL for that column */ function columnSql(array $cd) { $line = array(); $line[] = parent::columnSql($cd); /* if ($table['foreign keys'][$name]) { foreach ($table['foreign keys'][$name] as $foreignTable => $foreignColumn) { $line[] = 'references'; $line[] = $this->quoteIdentifier($foreignTable); $line[] = '(' . $this->quoteIdentifier($foreignColumn) . ')'; } } */ return implode(' ', $line); } /** * Append phrase(s) to an array of partial ALTER TABLE chunks in order * to alter the given column from its old state to a new one. * * @param array $phrase * @param string $columnName * @param array $old previous column definition as found in DB * @param array $cd current column definition */ function appendAlterModifyColumn(array &$phrase, $columnName, array $old, array $cd) { $prefix = 'ALTER COLUMN ' . $this->quoteIdentifier($columnName) . ' '; $oldType = $this->mapType($old); $newType = $this->mapType($cd); if ($oldType != $newType) { $phrase[] = $prefix . 'TYPE ' . $newType; } if (!empty($old['not null']) && empty($cd['not null'])) { $phrase[] = $prefix . 'DROP NOT NULL'; } else if (empty($old['not null']) && !empty($cd['not null'])) { $phrase[] = $prefix . 'SET NOT NULL'; } if (isset($old['default']) && !isset($cd['default'])) { $phrase[] = $prefix . 'DROP DEFAULT'; } else if (!isset($old['default']) && isset($cd['default'])) { $phrase[] = $prefix . 'SET DEFAULT ' . $this->quoteDefaultValue($cd); } } /** * Append an SQL statement to drop an index from a table. * Note that in PostgreSQL, index names are DB-unique. * * @param array $statements * @param string $table * @param string $name * @param array $def */ function appendDropIndex(array &$statements, $table, $name) { $statements[] = "DROP INDEX $name"; } /** * Quote a db/table/column identifier if necessary. * * @param string $name * @return string */ function quoteIdentifier($name) { return $this->conn->quoteIdentifier($name); } function mapType($column) { $map = array('serial' => 'bigserial', // FIXME: creates the wrong name for the sequence for some internal sequence-lookup function, so better fix this to do the real 'create sequence' dance. 'numeric' => 'decimal', 'datetime' => 'timestamp', 'blob' => 'bytea'); $type = $column['type']; if (isset($map[$type])) { $type = $map[$type]; } if ($type == 'int') { if (!empty($column['size'])) { $size = $column['size']; if ($size == 'small') { return 'int2'; } else if ($size == 'big') { return 'int8'; } } return 'int4'; } return $type; } // @fixme need name... :P function typeAndSize($column) { if ($column['type'] == 'enum') { $vals = array_map(array($this, 'quote'), $column['enum']); return "text check ($name in " . implode(',', $vals) . ')'; } else { return parent::typeAndSize($column); } } /** * Filter the given table definition array to match features available * in this database. * * This lets us strip out unsupported things like comments, foreign keys, * or type variants that we wouldn't get back from getTableDef(). * * @param array $tableDef */ function filterDef(array $tableDef) { foreach ($tableDef['fields'] as $name => &$col) { // No convenient support for field descriptions unset($col['description']); /* if (isset($col['size'])) { // Don't distinguish between tinyint and int. if ($col['size'] == 'tiny' && $col['type'] == 'int') { unset($col['size']); } } */ $col['type'] = $this->mapType($col); unset($col['size']); } if (!empty($tableDef['primary key'])) { $tableDef['primary key'] = $this->filterKeyDef($tableDef['primary key']); } if (!empty($tableDef['unique keys'])) { foreach ($tableDef['unique keys'] as $i => $def) { $tableDef['unique keys'][$i] = $this->filterKeyDef($def); } } return $tableDef; } /** * Filter the given key/index definition to match features available * in this database. * * @param array $def * @return array */ function filterKeyDef(array $def) { // PostgreSQL doesn't like prefix lengths specified on keys...? foreach ($def as $i => $item) { if (is_array($item)) { $def[$i] = $item[0]; } } return $def; } }