diff options
Diffstat (limited to 'includes/database.pgsql.inc')
| -rw-r--r-- | includes/database.pgsql.inc | 95 |
1 files changed, 84 insertions, 11 deletions
diff --git a/includes/database.pgsql.inc b/includes/database.pgsql.inc index 5778aac10..ab2f591ad 100644 --- a/includes/database.pgsql.inc +++ b/includes/database.pgsql.inc @@ -559,6 +559,22 @@ function _db_create_key_sql($fields) { return implode(', ', $ret); } +function _db_create_keys(&$ret, $table, $new_keys) { + if (isset($new_keys['primary key'])) { + db_add_primary_key($ret, $table, $new_keys['primary key']); + } + if (isset($new_keys['unique keys'])) { + foreach ($new_keys['unique keys'] as $name => $fields) { + db_add_unique_key($ret, $table, $name, $fields); + } + } + if (isset($new_keys['indexes'])) { + foreach ($new_keys['indexes'] as $name => $fields) { + db_add_index($ret, $table, $name, $fields); + } + } +} + /** * Set database-engine specific properties for a field. * @@ -665,8 +681,15 @@ function db_drop_table(&$ret, $table) { * created field will be set to the value of the key in all rows. * This is most useful for creating NOT NULL columns with no default * value in existing tables. - */ -function db_add_field(&$ret, $table, $field, $spec) { + * @param $keys_new + * Optional keys and indexes specification to be created on the + * table along with adding the field. The format is the same as a + * table specification but without the 'fields' element. If you are + * adding a type 'serial' field, you MUST specify at least one key + * or index including it in this array. @see db_change_field for more + * explanation why. + */ +function db_add_field(&$ret, $table, $field, $spec, $new_keys = array()) { $fixnull = FALSE; if (!empty($spec['not null']) && !isset($spec['default'])) { $fixnull = TRUE; @@ -684,6 +707,9 @@ function db_add_field(&$ret, $table, $field, $spec) { if ($fixnull) { $ret[] = update_sql("ALTER TABLE {". $table ."} ALTER $field SET NOT NULL"); } + if (isset($new_keys)) { + _db_create_keys($ret, $table, $new_keys); + } } /** @@ -831,14 +857,49 @@ function db_drop_index(&$ret, $table, $name) { /** * Change a field definition. * - * IMPORTANT NOTE: On some database systems (notably PostgreSQL), - * changing a field definition involves adding a new field and - * dropping an old one. This means that any indices, primary keys and - * sequences (from serial-type fields) that use the field to be - * changed get dropped. For database portability, you MUST drop them - * explicitly before calling db_change_field() and then re-create them - * afterwards. Use db_{add,drop}_{primary_key,unique_key,index} for - * this purpose. + * IMPORTANT NOTE: To maintain database portability, you have to explicitly + * recreate all indices and primary keys that are using the changed field. + * + * That means that you have to drop all affected keys and indexes with + * db_drop_{primary_key,unique_key,index}() before calling db_change_field(). + * To recreate the keys and indices, pass the key definitions as the + * optional $new_keys argument directly to db_change_field(). + * + * For example, suppose you have: + * @code + * $schema['foo'] = array( + * 'fields' => array( + * 'bar' => array('type' => 'int', 'not null' => TRUE) + * ), + * 'primary key' => array('bar') + * ); + * @endcode + * and you want to change foo.bar to be type serial, leaving it as the + * primary key. The correct sequence is: + * @code + * db_drop_primary_key($ret, 'foo'); + * db_change_field($ret, 'foo', 'bar', 'bar', + * array('type' => 'serial', 'not null' => TRUE), + * array('primary key' => array('bar'))); + * @endcode + * + * The reasons for this are due to the different database engines: + * + * On PostgreSQL, changing a field definition involves adding a new field + * and dropping an old one which* causes any indices, primary keys and + * sequences (from serial-type fields) that use the changed field to be dropped. + * + * On MySQL, all type 'serial' fields must be part of at least one key + * or index as soon as they are created. You cannot use + * db_add_{primary_key,unique_key,index}() for this purpose because + * the ALTER TABLE command will fail to add the column without a key + * or index specification. The solution is to use the optional + * $new_keys argument to create the key or index at the same time as + * field. + * + * You could use db_add_{primary_key,unique_key,index}() in all cases + * unless you are converting a field to be type serial. You can use + * the $new_keys argument in all cases. * * @param $ret * Array to which query results will be added. @@ -850,17 +911,29 @@ function db_drop_index(&$ret, $table, $name) { * New name for the field (set to the same as $field if you don't want to change the name). * @param $spec * The field specification for the new field. + * @param $new_keys + * Optional keys and indexes specification to be created on the + * table along with changing the field. The format is the same as a + * table specification but without the 'fields' element. */ -function db_change_field(&$ret, $table, $field, $field_new, $spec) { +function db_change_field(&$ret, $table, $field, $field_new, $spec, $new_keys = array()) { $ret[] = update_sql("ALTER TABLE {". $table ."} RENAME $field TO ". $field ."_old"); $not_null = isset($spec['not null']) ? $spec['not null'] : FALSE; unset($spec['not null']); + db_add_field($ret, $table, "$field_new", $spec); + $ret[] = update_sql("UPDATE {". $table ."} SET $field_new = ". $field ."_old"); + if ($not_null) { $ret[] = update_sql("ALTER TABLE {". $table ."} ALTER $field_new SET NOT NULL"); } + db_drop_field($ret, $table, $field .'_old'); + + if (isset($new_keys)) { + _db_create_keys($ret, $table, $new_keys); + } } /** |