3 * StatusNet, the distributed open-source microblogging tool
5 * Database schema utilities
9 * LICENCE: This program is free software: you can redistribute it and/or modify
10 * it under the terms of the GNU Affero General Public License as published by
11 * the Free Software Foundation, either version 3 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU Affero General Public License for more details.
19 * You should have received a copy of the GNU Affero General Public License
20 * along with this program. If not, see <http://www.gnu.org/licenses/>.
24 * @author Evan Prodromou <evan@status.net>
25 * @copyright 2009 StatusNet, Inc.
26 * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
27 * @link http://status.net/
30 if (!defined('STATUSNET')) {
35 * Class representing the database schema
37 * A class representing the database schema. Can be used to
38 * manipulate the schema -- especially for plugins and upgrade
43 * @author Evan Prodromou <evan@status.net>
44 * @author Brenda Wallace <shiny@cpan.org>
45 * @author Brion Vibber <brion@status.net>
46 * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
47 * @link http://status.net/
50 class PgsqlSchema extends Schema
54 * Returns a table definition array for the table
55 * in the schema with the given name.
57 * Throws an exception if the table is not found.
59 * @param string $table Name of the table to get
61 * @return array tabledef for that table.
64 public function getTableDef($table)
69 // Pull column data from INFORMATION_SCHEMA
70 $columns = $this->fetchMetaInfo($table, 'columns', 'ordinal_position');
71 if (count($columns) == 0) {
72 throw new SchemaTableMissingException("No such table: $table");
75 // We'll need to match up fields by ordinal reference
76 $orderedFields = array();
78 foreach ($columns as $row) {
80 $name = $row['column_name'];
81 $orderedFields[$row['ordinal_position']] = $name;
86 list($type, $size) = $this->reverseMapType($row['udt_name']);
87 $field['type'] = $type;
89 $field['size'] = $size;
92 if ($type == 'char' || $type == 'varchar') {
93 if ($row['character_maximum_length'] !== null) {
94 $field['length'] = intval($row['character_maximum_length']);
97 if ($type == 'numeric') {
98 // Other int types may report these values, but they're irrelevant.
100 if ($row['numeric_precision'] !== null) {
101 $field['precision'] = intval($row['numeric_precision']);
103 if ($row['numeric_scale'] !== null) {
104 $field['scale'] = intval($row['numeric_scale']);
107 if ($row['is_nullable'] == 'NO') {
108 $field['not null'] = true;
110 if ($row['column_default'] !== null) {
111 $field['default'] = $row['column_default'];
112 if ($this->isNumericType($type)) {
113 $field['default'] = intval($field['default']);
117 $def['fields'][$name] = $field;
120 // Pulling index info from pg_class & pg_index
121 // This can give us primary & unique key info, but not foreign key constraints
122 // so we exclude them and pick them up later.
123 $indexInfo = $this->getIndexInfo($table);
124 foreach ($indexInfo as $row) {
125 $keyName = $row['key_name'];
127 // Dig the column references out!
129 // These are inconvenient arrays with partial references to the
130 // pg_att table, but since we've already fetched up the column
131 // info on the current table, we can look those up locally.
133 $colPositions = explode(' ', $row['indkey']);
134 foreach ($colPositions as $ord) {
136 $cols[] = 'FUNCTION'; // @fixme
138 $cols[] = $orderedFields[$ord];
142 $def['indexes'][$keyName] = $cols;
145 // Pull constraint data from INFORMATION_SCHEMA:
146 // Primary key, unique keys, foreign keys
147 $keyColumns = $this->fetchMetaInfo($table, 'key_column_usage', 'constraint_name,ordinal_position');
150 foreach ($keyColumns as $row) {
151 $keyName = $row['constraint_name'];
152 $keyCol = $row['column_name'];
153 if (!isset($keys[$keyName])) {
154 $keys[$keyName] = array();
156 $keys[$keyName][] = $keyCol;
159 foreach ($keys as $keyName => $cols) {
160 // name hack -- is this reliable?
161 if ($keyName == "{$table}_pkey") {
162 $def['primary key'] = $cols;
163 } else if (preg_match("/^{$table}_(.*)_fkey$/", $keyName, $matches)) {
164 $fkey = $this->getForeignKeyInfo($table, $keyName);
165 $colMap = array_combine($cols, $fkey['col_names']);
166 $def['foreign keys'][$keyName] = array($fkey['table_name'], $colMap);
168 $def['unique keys'][$keyName] = $cols;
175 * Pull some INFORMATION.SCHEMA data for the given table.
177 * @param string $table
178 * @return array of arrays
180 function fetchMetaInfo($table, $infoTable, $orderBy=null)
182 $query = "SELECT * FROM information_schema.%s " .
183 "WHERE table_name='%s'";
184 $sql = sprintf($query, $infoTable, $table);
186 $sql .= ' ORDER BY ' . $orderBy;
188 return $this->fetchQueryData($sql);
192 * Pull some PG-specific index info
193 * @param string $table
194 * @return array of arrays
196 function getIndexInfo($table)
199 '(SELECT relname FROM pg_class WHERE oid=indexrelid) AS key_name, ' .
201 'WHERE indrelid=(SELECT oid FROM pg_class WHERE relname=\'%s\') ' .
202 'AND indisprimary=\'f\' AND indisunique=\'f\' ' .
203 'ORDER BY indrelid, indexrelid';
204 $sql = sprintf($query, $table);
205 return $this->fetchQueryData($sql);
209 * Column names from the foreign table can be resolved with a call to getTableColumnNames()
210 * @param <type> $table
211 * @return array array of rows with keys: fkey_name, table_name, table_id, col_names (array of strings)
213 function getForeignKeyInfo($table, $constraint_name)
215 // In a sane world, it'd be easier to query the column names directly.
216 // But it's pretty hard to work with arrays such as col_indexes in direct SQL here.
218 '(SELECT relname FROM pg_class WHERE oid=confrelid) AS table_name, ' .
219 'confrelid AS table_id, ' .
220 '(SELECT indkey FROM pg_index WHERE indexrelid=conindid) AS col_indexes ' .
221 'FROM pg_constraint ' .
222 'WHERE conrelid=(SELECT oid FROM pg_class WHERE relname=\'%s\') ' .
223 'AND conname=\'%s\' ' .
225 $sql = sprintf($query, $table, $constraint_name);
226 $data = $this->fetchQueryData($sql);
227 if (count($data) < 1) {
228 throw new Exception("Could not find foreign key " . $constraint_name . " on table " . $table);
233 'table_name' => $row['table_name'],
234 'col_names' => $this->getTableColumnNames($row['table_id'], $row['col_indexes'])
240 * @param int $table_id
241 * @param array $col_indexes
242 * @return array of strings
244 function getTableColumnNames($table_id, $col_indexes)
246 $indexes = array_map('intval', explode(' ', $col_indexes));
247 $query = 'SELECT attnum AS col_index, attname AS col_name ' .
248 'FROM pg_attribute where attrelid=%d ' .
249 'AND attnum IN (%s)';
250 $sql = sprintf($query, $table_id, implode(',', $indexes));
251 $data = $this->fetchQueryData($sql);
254 foreach ($data as $row) {
255 $byId[$row['col_index']] = $row['col_name'];
259 foreach ($indexes as $id) {
266 * Translate the (mostly) mysql-ish column types into somethings more standard
267 * @param string column type
269 * @return string postgres happy column type
271 private function _columnTypeTranslation($type) {
273 'datetime' => 'timestamp',
275 if(!empty($map[$type])) {
282 * Return the proper SQL for creating or
285 * Appropriate for use in CREATE TABLE or
286 * ALTER TABLE statements.
288 * @param array $cd column to create
290 * @return string correct SQL for that column
293 function columnSql(array $cd)
296 $line[] = parent::columnSql($cd);
299 if ($table['foreign keys'][$name]) {
300 foreach ($table['foreign keys'][$name] as $foreignTable => $foreignColumn) {
301 $line[] = 'references';
302 $line[] = $this->quoteIdentifier($foreignTable);
303 $line[] = '(' . $this->quoteIdentifier($foreignColumn) . ')';
308 return implode(' ', $line);
312 * Append phrase(s) to an array of partial ALTER TABLE chunks in order
313 * to alter the given column from its old state to a new one.
315 * @param array $phrase
316 * @param string $columnName
317 * @param array $old previous column definition as found in DB
318 * @param array $cd current column definition
320 function appendAlterModifyColumn(array &$phrase, $columnName, array $old, array $cd)
322 $prefix = 'ALTER COLUMN ' . $this->quoteIdentifier($columnName) . ' ';
324 $oldType = $this->mapType($old);
325 $newType = $this->mapType($cd);
326 if ($oldType != $newType) {
327 $phrase[] = $prefix . 'TYPE ' . $newType;
330 if (!empty($old['not null']) && empty($cd['not null'])) {
331 $phrase[] = $prefix . 'DROP NOT NULL';
332 } else if (empty($old['not null']) && !empty($cd['not null'])) {
333 $phrase[] = $prefix . 'SET NOT NULL';
336 if (isset($old['default']) && !isset($cd['default'])) {
337 $phrase[] = $prefix . 'DROP DEFAULT';
338 } else if (!isset($old['default']) && isset($cd['default'])) {
339 $phrase[] = $prefix . 'SET DEFAULT ' . $this->quoteDefaultValue($cd);
344 * Quote a db/table/column identifier if necessary.
346 * @param string $name
349 function quoteIdentifier($name)
351 return '"' . $name . '"';
354 function mapType($column)
356 $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.
357 'numeric' => 'decimal',
358 'datetime' => 'timestamp',
361 $type = $column['type'];
362 if (isset($map[$type])) {
366 if (!empty($column['size'])) {
367 $size = $column['size'];
368 if ($type == 'integer' &&
369 in_array($size, array('small', 'big'))) {
370 $type = $size . 'int';
377 // @fixme need name... :P
378 function typeAndSize($column)
380 if ($column['type'] == 'enum') {
381 $vals = array_map(array($this, 'quote'), $column['enum']);
382 return "text check ($name in " . implode(',', $vals) . ')';
384 return parent::typeAndSize($column);
389 * Map a native type back to an independent type + size
391 * @param string $type
392 * @return array ($type, $size) -- $size may be null
394 protected function reverseMapType($type)
396 $type = strtolower($type);
398 'int4' => array('int', null),
399 'int8' => array('int', 'big'),
400 'bytea' => array('blob', null),
402 if (isset($map[$type])) {
405 return array($type, null);
410 * Filter the given table definition array to match features available
413 * This lets us strip out unsupported things like comments, foreign keys,
414 * or type variants that we wouldn't get back from getTableDef().
416 * @param array $tableDef
418 function filterDef(array $tableDef)
420 foreach ($tableDef['fields'] as $name => &$col) {
421 // No convenient support for field descriptions
422 unset($col['description']);
424 if (isset($col['size'])) {
425 // Don't distinguish between tinyint and int.
426 if ($col['size'] == 'tiny' && $col['type'] == 'int') {