1 <?php

     2 // $Id: database.pgsql.inc,v 1.68.2.5 2009/06/09 10:53:52 goba Exp $

     3 

     4 /**

     5  * @file

     6  * Database interface code for PostgreSQL database servers.

     7  */

     8 

     9 /**

    10  * @ingroup database

    11  * @{

    12  */

    13 

    14 /**

    15  * Report database status.

    16  */

    17 function db_status_report() {

    18   $t = get_t();

    19 

    20   $version = db_version();

    21 

    22   $form['pgsql'] = array(

    23     'title' => $t('PostgreSQL database'),

    24     'value' => $version,

    25   );

    26 

    27   if (version_compare($version, DRUPAL_MINIMUM_PGSQL) < 0) {

    28     $form['pgsql']['severity'] = REQUIREMENT_ERROR;

    29     $form['pgsql']['description'] = $t('Your PostgreSQL Server is too old. Drupal requires at least PostgreSQL %version.', array('%version' => DRUPAL_MINIMUM_PGSQL));

    30   }

    31 

    32   return $form;

    33 }

    34 

    35 /**

    36  * Returns the version of the database server currently in use.

    37  *

    38  * @return Database server version

    39  */

    40 function db_version() {

    41   return db_result(db_query("SHOW SERVER_VERSION"));

    42 }

    43 

    44 /**

    45  * Initialize a database connection.

    46  */

    47 function db_connect($url) {

    48   // Check if PostgreSQL support is present in PHP

    49   if (!function_exists('pg_connect')) {

    50     _db_error_page('Unable to use the PostgreSQL database because the PostgreSQL extension for PHP is not installed. Check your <code>php.ini</code> to see how you can enable it.');

    51   }

    52 

    53   $url = parse_url($url);

    54   $conn_string = '';

    55 

    56   // Decode url-encoded information in the db connection string

    57   if (isset($url['user'])) {

    58     $conn_string .= ' user='. urldecode($url['user']);

    59   }

    60   if (isset($url['pass'])) {

    61     $conn_string .= ' password='. urldecode($url['pass']);

    62   }

    63   if (isset($url['host'])) {

    64     $conn_string .= ' host='. urldecode($url['host']);

    65   }

    66   if (isset($url['path'])) {

    67     $conn_string .= ' dbname='. substr(urldecode($url['path']), 1);

    68   }

    69   if (isset($url['port'])) {

    70     $conn_string .= ' port='. urldecode($url['port']);

    71   }

    72 

    73   // pg_last_error() does not return a useful error message for database

    74   // connection errors. We must turn on error tracking to get at a good error

    75   // message, which will be stored in $php_errormsg.

    76   $track_errors_previous = ini_get('track_errors');

    77   ini_set('track_errors', 1);

    78 

    79   $connection = @pg_connect($conn_string);

    80   if (!$connection) {

    81     require_once './includes/unicode.inc';

    82     _db_error_page(decode_entities($php_errormsg));

    83   }

    84 

    85   // Restore error tracking setting

    86   ini_set('track_errors', $track_errors_previous);

    87 

    88   pg_query($connection, "set client_encoding=\"UTF8\"");

    89   return $connection;

    90 }

    91 

    92 /**

    93  * Runs a basic query in the active database.

    94  *

    95  * User-supplied arguments to the query should be passed in as separate

    96  * parameters so that they can be properly escaped to avoid SQL injection

    97  * attacks.

    98  *

    99  * @param $query

   100  *   A string containing an SQL query.

   101  * @param ...

   102  *   A variable number of arguments which are substituted into the query

   103  *   using printf() syntax. Instead of a variable number of query arguments,

   104  *   you may also pass a single array containing the query arguments.

   105  *

   106  *   Valid %-modifiers are: %s, %d, %f, %b (binary data, do not enclose

   107  *   in '') and %%.

   108  *

   109  *   NOTE: using this syntax will cast NULL and FALSE values to decimal 0,

   110  *   and TRUE values to decimal 1.

   111  *

   112  * @return

   113  *   A database query result resource, or FALSE if the query was not

   114  *   executed correctly.

   115  */

   116 function db_query($query) {

   117   $args = func_get_args();

   118   array_shift($args);

   119   $query = db_prefix_tables($query);

   120   if (isset($args[0]) and is_array($args[0])) { // 'All arguments in one array' syntax

   121     $args = $args[0];

   122   }

   123   _db_query_callback($args, TRUE);

   124   $query = preg_replace_callback(DB_QUERY_REGEXP, '_db_query_callback', $query);

   125   return _db_query($query);

   126 }

   127 

   128 /**

   129  * Helper function for db_query().

   130  */

   131 function _db_query($query, $debug = 0) {

   132   global $active_db, $last_result, $queries;

   133 

   134   if (variable_get('dev_query', 0)) {

   135     list($usec, $sec) = explode(' ', microtime());

   136     $timer = (float)$usec + (float)$sec;

   137   }

   138 

   139   $last_result = pg_query($active_db, $query);

   140 

   141   if (variable_get('dev_query', 0)) {

   142     $bt = debug_backtrace();

   143     $query = $bt[2]['function'] ."\n". $query;

   144     list($usec, $sec) = explode(' ', microtime());

   145     $stop = (float)$usec + (float)$sec;

   146     $diff = $stop - $timer;

   147     $queries[] = array($query, $diff);

   148   }

   149 

   150   if ($debug) {

   151     print '<p>query: '. $query .'<br />error:'. pg_last_error($active_db) .'</p>';

   152   }

   153 

   154   if ($last_result !== FALSE) {

   155     return $last_result;

   156   }

   157   else {

   158     // Indicate to drupal_error_handler that this is a database error.

   159     ${DB_ERROR} = TRUE;

   160     trigger_error(check_plain(pg_last_error($active_db) ."\nquery: ". $query), E_USER_WARNING);

   161     return FALSE;

   162   }

   163 }

   164 

   165 /**

   166  * Fetch one result row from the previous query as an object.

   167  *

   168  * @param $result

   169  *   A database query result resource, as returned from db_query().

   170  * @return

   171  *   An object representing the next row of the result, or FALSE. The attributes

   172  *   of this object are the table fields selected by the query.

   173  */

   174 function db_fetch_object($result) {

   175   if ($result) {

   176     return pg_fetch_object($result);

   177   }

   178 }

   179 

   180 /**

   181  * Fetch one result row from the previous query as an array.

   182  *

   183  * @param $result

   184  *   A database query result resource, as returned from db_query().

   185  * @return

   186  *   An associative array representing the next row of the result, or FALSE.

   187  *   The keys of this object are the names of the table fields selected by the

   188  *   query, and the values are the field values for this result row.

   189  */

   190 function db_fetch_array($result) {

   191   if ($result) {

   192     return pg_fetch_assoc($result);

   193   }

   194 }

   195 

   196 /**

   197  * Return an individual result field from the previous query.

   198  *

   199  * Only use this function if exactly one field is being selected; otherwise,

   200  * use db_fetch_object() or db_fetch_array().

   201  *

   202  * @param $result

   203  *   A database query result resource, as returned from db_query().

   204  * @return

   205  *   The resulting field or FALSE.

   206  */

   207 function db_result($result) {

   208   if ($result && pg_num_rows($result) > 0) {

   209     $array = pg_fetch_row($result);

   210     return $array[0];

   211   }

   212   return FALSE;

   213 }

   214 

   215 /**

   216  * Determine whether the previous query caused an error.

   217  */

   218 function db_error() {

   219   global $active_db;

   220   return pg_last_error($active_db);

   221 }

   222 

   223 /**

   224  * Returns the last insert id. This function is thread safe.

   225  *

   226  * @param $table

   227  *   The name of the table you inserted into.

   228  * @param $field

   229  *   The name of the autoincrement field.

   230  */

   231 function db_last_insert_id($table, $field) {

   232   return db_result(db_query("SELECT CURRVAL('{". db_escape_table($table) ."}_". db_escape_table($field) ."_seq')"));

   233 }

   234 

   235 /**

   236  * Determine the number of rows changed by the preceding query.

   237  */

   238 function db_affected_rows() {

   239   global $last_result;

   240   return empty($last_result) ? 0 : pg_affected_rows($last_result);

   241 }

   242 

   243 /**

   244  * Runs a limited-range query in the active database.

   245  *

   246  * Use this as a substitute for db_query() when a subset of the query

   247  * is to be returned.

   248  * User-supplied arguments to the query should be passed in as separate

   249  * parameters so that they can be properly escaped to avoid SQL injection

   250  * attacks.

   251  *

   252  * @param $query

   253  *   A string containing an SQL query.

   254  * @param ...

   255  *   A variable number of arguments which are substituted into the query

   256  *   using printf() syntax. Instead of a variable number of query arguments,

   257  *   you may also pass a single array containing the query arguments.

   258  *   Valid %-modifiers are: %s, %d, %f, %b (binary data, do not enclose

   259  *   in '') and %%.

   260  *

   261  *   NOTE: using this syntax will cast NULL and FALSE values to decimal 0,

   262  *   and TRUE values to decimal 1.

   263  *

   264  * @param $from

   265  *   The first result row to return.

   266  * @param $count

   267  *   The maximum number of result rows to return.

   268  * @return

   269  *   A database query result resource, or FALSE if the query was not executed

   270  *   correctly.

   271  */

   272 function db_query_range($query) {

   273   $args = func_get_args();

   274   $count = array_pop($args);

   275   $from = array_pop($args);

   276   array_shift($args);

   277 

   278   $query = db_prefix_tables($query);

   279   if (isset($args[0]) and is_array($args[0])) { // 'All arguments in one array' syntax

   280     $args = $args[0];

   281   }

   282   _db_query_callback($args, TRUE);

   283   $query = preg_replace_callback(DB_QUERY_REGEXP, '_db_query_callback', $query);

   284   $query .= ' LIMIT '. (int)$count .' OFFSET '. (int)$from;

   285   return _db_query($query);

   286 }

   287 

   288 /**

   289  * Runs a SELECT query and stores its results in a temporary table.

   290  *

   291  * Use this as a substitute for db_query() when the results need to stored

   292  * in a temporary table. Temporary tables exist for the duration of the page

   293  * request.

   294  * User-supplied arguments to the query should be passed in as separate parameters

   295  * so that they can be properly escaped to avoid SQL injection attacks.

   296  *

   297  * Note that if you need to know how many results were returned, you should do

   298  * a SELECT COUNT(*) on the temporary table afterwards. db_affected_rows() does

   299  * not give consistent result across different database types in this case.

   300  *

   301  * @param $query

   302  *   A string containing a normal SELECT SQL query.

   303  * @param ...

   304  *   A variable number of arguments which are substituted into the query

   305  *   using printf() syntax. The query arguments can be enclosed in one

   306  *   array instead.

   307  *   Valid %-modifiers are: %s, %d, %f, %b (binary data, do not enclose

   308  *   in '') and %%.

   309  *

   310  *   NOTE: using this syntax will cast NULL and FALSE values to decimal 0,

   311  *   and TRUE values to decimal 1.

   312  *

   313  * @param $table

   314  *   The name of the temporary table to select into. This name will not be

   315  *   prefixed as there is no risk of collision.

   316  * @return

   317  *   A database query result resource, or FALSE if the query was not executed

   318  *   correctly.

   319  */

   320 function db_query_temporary($query) {

   321   $args = func_get_args();

   322   $tablename = array_pop($args);

   323   array_shift($args);

   324 

   325   $query = preg_replace('/^SELECT/i', 'CREATE TEMPORARY TABLE '. $tablename .' AS SELECT', db_prefix_tables($query));

   326   if (isset($args[0]) and is_array($args[0])) { // 'All arguments in one array' syntax

   327     $args = $args[0];

   328   }

   329   _db_query_callback($args, TRUE);

   330   $query = preg_replace_callback(DB_QUERY_REGEXP, '_db_query_callback', $query);

   331   return _db_query($query);

   332 }

   333 

   334 /**

   335  * Returns a properly formatted Binary Large OBject value.

   336  * In case of PostgreSQL encodes data for insert into bytea field.

   337  *

   338  * @param $data

   339  *   Data to encode.

   340  * @return

   341  *  Encoded data.

   342  */

   343 function db_encode_blob($data) {

   344   return "'". pg_escape_bytea($data) ."'";

   345 }

   346 

   347 /**

   348  * Returns text from a Binary Large OBject value.

   349  * In case of PostgreSQL decodes data after select from bytea field.

   350  *

   351  * @param $data

   352  *   Data to decode.

   353  * @return

   354  *  Decoded data.

   355  */

   356 function db_decode_blob($data) {

   357   return pg_unescape_bytea($data);

   358 }

   359 

   360 /**

   361  * Prepare user input for use in a database query, preventing SQL injection attacks.

   362  * Note: This function requires PostgreSQL 7.2 or later.

   363  */

   364 function db_escape_string($text) {

   365   return pg_escape_string($text);

   366 }

   367 

   368 /**

   369  * Lock a table.

   370  * This function automatically starts a transaction.

   371  */

   372 function db_lock_table($table) {

   373   db_query('BEGIN; LOCK TABLE {'. db_escape_table($table) .'} IN EXCLUSIVE MODE');

   374 }

   375 

   376 /**

   377  * Unlock all locked tables.

   378  * This function automatically commits a transaction.

   379  */

   380 function db_unlock_tables() {

   381   db_query('COMMIT');

   382 }

   383 

   384 /**

   385  * Check if a table exists.

   386  */

   387 function db_table_exists($table) {

   388   return (bool) db_result(db_query("SELECT COUNT(*) FROM pg_class WHERE relname = '{". db_escape_table($table) ."}'"));

   389 }

   390 

   391 /**

   392  * Check if a column exists in the given table.

   393  */

   394 function db_column_exists($table, $column) {

   395   return (bool) db_result(db_query("SELECT COUNT(pg_attribute.attname) FROM pg_class, pg_attribute WHERE pg_attribute.attrelid = pg_class.oid AND pg_class.relname = '{". db_escape_table($table) ."}' AND attname = '". db_escape_table($column) ."'"));

   396 }

   397 

   398 /**

   399  * Verify if the database is set up correctly.

   400  */

   401 function db_check_setup() {

   402   $t = get_t();

   403 

   404   $encoding = db_result(db_query('SHOW server_encoding'));

   405   if (!in_array(strtolower($encoding), array('unicode', 'utf8'))) {

   406     drupal_set_message($t('Your PostgreSQL database is set up with the wrong character encoding (%encoding). It is possible it will not work as expected. It is advised to recreate it with UTF-8/Unicode encoding. More information can be found in the <a href="@url">PostgreSQL documentation</a>.', array('%encoding' => $encoding, '@url' => 'http://www.postgresql.org/docs/7.4/interactive/multibyte.html')), 'status');

   407   }

   408 }

   409 

   410 /**

   411  * Wraps the given table.field entry with a DISTINCT(). The wrapper is added to

   412  * the SELECT list entry of the given query and the resulting query is returned.

   413  * This function only applies the wrapper if a DISTINCT doesn't already exist in

   414  * the query.

   415  *

   416  * @param $table Table containing the field to set as DISTINCT

   417  * @param $field Field to set as DISTINCT

   418  * @param $query Query to apply the wrapper to

   419  * @return SQL query with the DISTINCT wrapper surrounding the given table.field.

   420  */

   421 function db_distinct_field($table, $field, $query) {

   422   if (!preg_match('/FROM\s+\S+\s+AS/si', $query)

   423   && !preg_match('/DISTINCT\s+ON\s*\(\s*(' . $table . '\s*\.\s*)?' . $field . '\s*\)/si', $query)

   424   && !preg_match('/DISTINCT[ (]' . $field . '/si', $query)

   425   && preg_match('/(.*FROM\s+)(.*?\s)(\s*(WHERE|GROUP|HAVING|ORDER|LIMIT|FOR).*)/Asi', $query, $m)) {

   426     $query = $m[1];

   427     $query .= preg_replace('/([\{\w+\}]+)\s+(' . $table . ')\s/Usi', '(SELECT DISTINCT ON (' . $field . ') * FROM \1) \2 ', $m[2]);

   428     $query .= $m[3];

   429   }

   430   return $query;

   431 }

   432 

   433 /**

   434  * @} End of "ingroup database".

   435  */

   436 

   437 /**

   438  * @ingroup schemaapi

   439  * @{

   440  */

   441 

   442 /**

   443  * This maps a generic data type in combination with its data size

   444  * to the engine-specific data type.

   445  */

   446 function db_type_map() {

   447   // Put :normal last so it gets preserved by array_flip.  This makes

   448   // it much easier for modules (such as schema.module) to map

   449   // database types back into schema types.

   450   $map = array(

   451     'varchar:normal' => 'varchar',

   452     'char:normal' => 'character',

   453 

   454     'text:tiny' => 'text',

   455     'text:small' => 'text',

   456     'text:medium' => 'text',

   457     'text:big' => 'text',

   458     'text:normal' => 'text',

   459 

   460     'int:tiny' => 'smallint',

   461     'int:small' => 'smallint',

   462     'int:medium' => 'int',

   463     'int:big' => 'bigint',

   464     'int:normal' => 'int',

   465 

   466     'float:tiny' => 'real',

   467     'float:small' => 'real',

   468     'float:medium' => 'real',

   469     'float:big' => 'double precision',

   470     'float:normal' => 'real',

   471 

   472     'numeric:normal' => 'numeric',

   473 

   474     'blob:big' => 'bytea',

   475     'blob:normal' => 'bytea',

   476 

   477     'datetime:normal' => 'timestamp without time zone',

   478 

   479     'serial:tiny' => 'serial',

   480     'serial:small' => 'serial',

   481     'serial:medium' => 'serial',

   482     'serial:big' => 'bigserial',

   483     'serial:normal' => 'serial',

   484   );

   485   return $map;

   486 }

   487 

   488 /**

   489  * Generate SQL to create a new table from a Drupal schema definition.

   490  *

   491  * @param $name

   492  *   The name of the table to create.

   493  * @param $table

   494  *   A Schema API table definition array.

   495  * @return

   496  *   An array of SQL statements to create the table.

   497  */

   498 function db_create_table_sql($name, $table) {

   499   $sql_fields = array();

   500   foreach ($table['fields'] as $field_name => $field) {

   501     $sql_fields[] = _db_create_field_sql($field_name, _db_process_field($field));

   502   }

   503 

   504   $sql_keys = array();

   505   if (isset($table['primary key']) && is_array($table['primary key'])) {

   506     $sql_keys[] = 'PRIMARY KEY ('. implode(', ', $table['primary key']) .')';

   507   }

   508   if (isset($table['unique keys']) && is_array($table['unique keys'])) {

   509     foreach ($table['unique keys'] as $key_name => $key) {

   510       $sql_keys[] = 'CONSTRAINT {'. $name .'}_'. $key_name .'_key UNIQUE ('. implode(', ', $key) .')';

   511     }

   512   }

   513 

   514   $sql = "CREATE TABLE {". $name ."} (\n\t";

   515   $sql .= implode(",\n\t", $sql_fields);

   516   if (count($sql_keys) > 0) {

   517     $sql .= ",\n\t";

   518   }

   519   $sql .= implode(",\n\t", $sql_keys);

   520   $sql .= "\n)";

   521   $statements[] = $sql;

   522 

   523   if (isset($table['indexes']) && is_array($table['indexes'])) {

   524     foreach ($table['indexes'] as $key_name => $key) {

   525       $statements[] = _db_create_index_sql($name, $key_name, $key);

   526     }

   527   }

   528 

   529   return $statements;

   530 }

   531 

   532 function _db_create_index_sql($table, $name, $fields) {

   533   $query = 'CREATE INDEX {'. $table .'}_'. $name .'_idx ON {'. $table .'} (';

   534   $query .= _db_create_key_sql($fields) .')';

   535   return $query;

   536 }

   537 

   538 function _db_create_key_sql($fields) {

   539   $ret = array();

   540   foreach ($fields as $field) {

   541     if (is_array($field)) {

   542       $ret[] = 'substr('. $field[0] .', 1, '. $field[1] .')';

   543     }

   544     else {

   545       $ret[] = $field;

   546     }

   547   }

   548   return implode(', ', $ret);

   549 }

   550 

   551 function _db_create_keys(&$ret, $table, $new_keys) {

   552   if (isset($new_keys['primary key'])) {

   553     db_add_primary_key($ret, $table, $new_keys['primary key']);

   554   }

   555   if (isset($new_keys['unique keys'])) {

   556     foreach ($new_keys['unique keys'] as $name => $fields) {

   557       db_add_unique_key($ret, $table, $name, $fields);

   558     }

   559   }

   560   if (isset($new_keys['indexes'])) {

   561     foreach ($new_keys['indexes'] as $name => $fields) {

   562       db_add_index($ret, $table, $name, $fields);

   563     }

   564   }

   565 }

   566 

   567 /**

   568  * Set database-engine specific properties for a field.

   569  *

   570  * @param $field

   571  *   A field description array, as specified in the schema documentation.

   572  */

   573 function _db_process_field($field) {

   574   if (!isset($field['size'])) {

   575     $field['size'] = 'normal';

   576   }

   577   // Set the correct database-engine specific datatype.

   578   if (!isset($field['pgsql_type'])) {

   579     $map = db_type_map();

   580     $field['pgsql_type'] = $map[$field['type'] .':'. $field['size']];

   581   }

   582   if ($field['type'] == 'serial') {

   583     unset($field['not null']);

   584   }

   585   return $field;

   586 }

   587 

   588 /**

   589  * Create an SQL string for a field to be used in table creation or alteration.

   590  *

   591  * Before passing a field out of a schema definition into this function it has

   592  * to be processed by _db_process_field().

   593  *

   594  * @param $name

   595  *    Name of the field.

   596  * @param $spec

   597  *    The field specification, as per the schema data structure format.

   598  */

   599 function _db_create_field_sql($name, $spec) {

   600   $sql = $name .' '. $spec['pgsql_type'];

   601 

   602   if ($spec['type'] == 'serial') {

   603     unset($spec['not null']);

   604   }

   605   if (!empty($spec['unsigned'])) {

   606     if ($spec['type'] == 'serial') {

   607       $sql .= " CHECK ($name >= 0)";

   608     }

   609     else {

   610       $sql .= '_unsigned';

   611     }

   612   }

   613 

   614   if (!empty($spec['length'])) {

   615     $sql .= '('. $spec['length'] .')';

   616   }

   617   elseif (isset($spec['precision']) && isset($spec['scale'])) {

   618     $sql .= '('. $spec['precision'] .', '. $spec['scale'] .')';

   619   }

   620 

   621   if (isset($spec['not null']) && $spec['not null']) {

   622     $sql .= ' NOT NULL';

   623   }

   624   if (isset($spec['default'])) {

   625     $default = is_string($spec['default']) ? "'". $spec['default'] ."'" : $spec['default'];

   626     $sql .= " default $default";

   627   }

   628 

   629   return $sql;

   630 }

   631 

   632 /**

   633  * Rename a table.

   634  *

   635  * @param $ret

   636  *   Array to which query results will be added.

   637  * @param $table

   638  *   The table to be renamed.

   639  * @param $new_name

   640  *   The new name for the table.

   641  */

   642 function db_rename_table(&$ret, $table, $new_name) {

   643   $ret[] = update_sql('ALTER TABLE {'. $table .'} RENAME TO {'. $new_name .'}');

   644 }

   645 

   646 /**

   647  * Drop a table.

   648  *

   649  * @param $ret

   650  *   Array to which query results will be added.

   651  * @param $table

   652  *   The table to be dropped.

   653  */

   654 function db_drop_table(&$ret, $table) {

   655   $ret[] = update_sql('DROP TABLE {'. $table .'}');

   656 }

   657 

   658 /**

   659  * Add a new field to a table.

   660  *

   661  * @param $ret

   662  *   Array to which query results will be added.

   663  * @param $table

   664  *   Name of the table to be altered.

   665  * @param $field

   666  *   Name of the field to be added.

   667  * @param $spec

   668  *   The field specification array, as taken from a schema definition.

   669  *   The specification may also contain the key 'initial', the newly

   670  *   created field will be set to the value of the key in all rows.

   671  *   This is most useful for creating NOT NULL columns with no default

   672  *   value in existing tables.

   673  * @param $keys_new

   674  *   Optional keys and indexes specification to be created on the

   675  *   table along with adding the field. The format is the same as a

   676  *   table specification but without the 'fields' element.  If you are

   677  *   adding a type 'serial' field, you MUST specify at least one key

   678  *   or index including it in this array. @see db_change_field for more

   679  *   explanation why.

   680  */

   681 function db_add_field(&$ret, $table, $field, $spec, $new_keys = array()) {

   682   $fixnull = FALSE;

   683   if (!empty($spec['not null']) && !isset($spec['default'])) {

   684     $fixnull = TRUE;

   685     $spec['not null'] = FALSE;

   686   }

   687   $query = 'ALTER TABLE {'. $table .'} ADD COLUMN ';

   688   $query .= _db_create_field_sql($field, _db_process_field($spec));

   689   $ret[] = update_sql($query);

   690   if (isset($spec['initial'])) {

   691     // All this because update_sql does not support %-placeholders.

   692     $sql = 'UPDATE {'. $table .'} SET '. $field .' = '. db_type_placeholder($spec['type']);

   693     $result = db_query($sql, $spec['initial']);

   694     $ret[] = array('success' => $result !== FALSE, 'query' => check_plain($sql .' ('. $spec['initial'] .')'));

   695   }

   696   if ($fixnull) {

   697     $ret[] = update_sql("ALTER TABLE {". $table ."} ALTER $field SET NOT NULL");

   698   }

   699   if (isset($new_keys)) {

   700     _db_create_keys($ret, $table, $new_keys);

   701   }

   702 }

   703 

   704 /**

   705  * Drop a field.

   706  *

   707  * @param $ret

   708  *   Array to which query results will be added.

   709  * @param $table

   710  *   The table to be altered.

   711  * @param $field

   712  *   The field to be dropped.

   713  */

   714 function db_drop_field(&$ret, $table, $field) {

   715   $ret[] = update_sql('ALTER TABLE {'. $table .'} DROP COLUMN '. $field);

   716 }

   717 

   718 /**

   719  * Set the default value for a field.

   720  *

   721  * @param $ret

   722  *   Array to which query results will be added.

   723  * @param $table

   724  *   The table to be altered.

   725  * @param $field

   726  *   The field to be altered.

   727  * @param $default

   728  *   Default value to be set. NULL for 'default NULL'.

   729  */

   730 function db_field_set_default(&$ret, $table, $field, $default) {

   731   if ($default == NULL) {

   732     $default = 'NULL';

   733   }

   734   else {

   735     $default = is_string($default) ? "'$default'" : $default;

   736   }

   737 

   738   $ret[] = update_sql('ALTER TABLE {'. $table .'} ALTER COLUMN '. $field .' SET DEFAULT '. $default);

   739 }

   740 

   741 /**

   742  * Set a field to have no default value.

   743  *

   744  * @param $ret

   745  *   Array to which query results will be added.

   746  * @param $table

   747  *   The table to be altered.

   748  * @param $field

   749  *   The field to be altered.

   750  */

   751 function db_field_set_no_default(&$ret, $table, $field) {

   752   $ret[] = update_sql('ALTER TABLE {'. $table .'} ALTER COLUMN '. $field .' DROP DEFAULT');

   753 }

   754 

   755 /**

   756  * Add a primary key.

   757  *

   758  * @param $ret

   759  *   Array to which query results will be added.

   760  * @param $table

   761  *   The table to be altered.

   762  * @param $fields

   763  *   Fields for the primary key.

   764  */

   765 function db_add_primary_key(&$ret, $table, $fields) {

   766   $ret[] = update_sql('ALTER TABLE {'. $table .'} ADD PRIMARY KEY ('.

   767     implode(',', $fields) .')');

   768 }

   769 

   770 /**

   771  * Drop the primary key.

   772  *

   773  * @param $ret

   774  *   Array to which query results will be added.

   775  * @param $table

   776  *   The table to be altered.

   777  */

   778 function db_drop_primary_key(&$ret, $table) {

   779   $ret[] = update_sql('ALTER TABLE {'. $table .'} DROP CONSTRAINT {'. $table .'}_pkey');

   780 }

   781 

   782 /**

   783  * Add a unique key.

   784  *

   785  * @param $ret

   786  *   Array to which query results will be added.

   787  * @param $table

   788  *   The table to be altered.

   789  * @param $name

   790  *   The name of the key.

   791  * @param $fields

   792  *   An array of field names.

   793  */

   794 function db_add_unique_key(&$ret, $table, $name, $fields) {

   795   $name = '{'. $table .'}_'. $name .'_key';

   796   $ret[] = update_sql('ALTER TABLE {'. $table .'} ADD CONSTRAINT '.

   797     $name .' UNIQUE ('. implode(',', $fields) .')');

   798 }

   799 

   800 /**

   801  * Drop a unique key.

   802  *

   803  * @param $ret

   804  *   Array to which query results will be added.

   805  * @param $table

   806  *   The table to be altered.

   807  * @param $name

   808  *   The name of the key.

   809  */

   810 function db_drop_unique_key(&$ret, $table, $name) {

   811   $name = '{'. $table .'}_'. $name .'_key';

   812   $ret[] = update_sql('ALTER TABLE {'. $table .'} DROP CONSTRAINT '. $name);

   813 }

   814 

   815 /**

   816  * Add an index.

   817  *

   818  * @param $ret

   819  *   Array to which query results will be added.

   820  * @param $table

   821  *   The table to be altered.

   822  * @param $name

   823  *   The name of the index.

   824  * @param $fields

   825  *   An array of field names.

   826  */

   827 function db_add_index(&$ret, $table, $name, $fields) {

   828   $ret[] = update_sql(_db_create_index_sql($table, $name, $fields));

   829 }

   830 

   831 /**

   832  * Drop an index.

   833  *

   834  * @param $ret

   835  *   Array to which query results will be added.

   836  * @param $table

   837  *   The table to be altered.

   838  * @param $name

   839  *   The name of the index.

   840  */

   841 function db_drop_index(&$ret, $table, $name) {

   842   $name = '{'. $table .'}_'. $name .'_idx';

   843   $ret[] = update_sql('DROP INDEX '. $name);

   844 }

   845 

   846 /**

   847  * Change a field definition.

   848  *

   849  * IMPORTANT NOTE: To maintain database portability, you have to explicitly

   850  * recreate all indices and primary keys that are using the changed field.

   851  *

   852  * That means that you have to drop all affected keys and indexes with

   853  * db_drop_{primary_key,unique_key,index}() before calling db_change_field().

   854  * To recreate the keys and indices, pass the key definitions as the

   855  * optional $new_keys argument directly to db_change_field().

   856  *

   857  * For example, suppose you have:

   858  * @code

   859  * $schema['foo'] = array(

   860  *   'fields' => array(

   861  *     'bar' => array('type' => 'int', 'not null' => TRUE)

   862  *   ),

   863  *   'primary key' => array('bar')

   864  * );

   865  * @endcode

   866  * and you want to change foo.bar to be type serial, leaving it as the

   867  * primary key.  The correct sequence is:

   868  * @code

   869  * db_drop_primary_key($ret, 'foo');

   870  * db_change_field($ret, 'foo', 'bar', 'bar',

   871  *   array('type' => 'serial', 'not null' => TRUE),

   872  *   array('primary key' => array('bar')));

   873  * @endcode

   874  *

   875  * The reasons for this are due to the different database engines:

   876  *

   877  * On PostgreSQL, changing a field definition involves adding a new field

   878  * and dropping an old one which* causes any indices, primary keys and

   879  * sequences (from serial-type fields) that use the changed field to be dropped.

   880  *

   881  * On MySQL, all type 'serial' fields must be part of at least one key

   882  * or index as soon as they are created.  You cannot use

   883  * db_add_{primary_key,unique_key,index}() for this purpose because

   884  * the ALTER TABLE command will fail to add the column without a key

   885  * or index specification.  The solution is to use the optional

   886  * $new_keys argument to create the key or index at the same time as

   887  * field.

   888  *

   889  * You could use db_add_{primary_key,unique_key,index}() in all cases

   890  * unless you are converting a field to be type serial. You can use

   891  * the $new_keys argument in all cases.

   892  *

   893  * @param $ret

   894  *   Array to which query results will be added.

   895  * @param $table

   896  *   Name of the table.

   897  * @param $field

   898  *   Name of the field to change.

   899  * @param $field_new

   900  *   New name for the field (set to the same as $field if you don't want to change the name).

   901  * @param $spec

   902  *   The field specification for the new field.

   903  * @param $new_keys

   904  *   Optional keys and indexes specification to be created on the

   905  *   table along with changing the field. The format is the same as a

   906  *   table specification but without the 'fields' element.

   907  */

   908 function db_change_field(&$ret, $table, $field, $field_new, $spec, $new_keys = array()) {

   909   $ret[] = update_sql("ALTER TABLE {". $table ."} RENAME $field TO ". $field ."_old");

   910   $not_null = isset($spec['not null']) ? $spec['not null'] : FALSE;

   911   unset($spec['not null']);

   912 

   913   if (!array_key_exists('size', $spec)) {

   914     $spec['size'] = 'normal';

   915   }

   916   db_add_field($ret, $table, "$field_new", $spec);

   917 

   918   // We need to type cast the new column to best transfer the data

   919   // db_type_map will return possiblities that are not 'cast-able'

   920   // such as serial - they must be made 'int' instead.

   921   $map =  db_type_map();

   922   $typecast = $map[$spec['type'] .':'. $spec['size']];

   923   if (in_array($typecast, array('serial', 'bigserial', 'numeric'))) {

   924     $typecast = 'int';

   925   }

   926   $ret[] = update_sql('UPDATE {'. $table .'} SET '. $field_new .' = CAST('. $field .'_old AS '. $typecast .')');

   927 

   928   if ($not_null) {

   929     $ret[] = update_sql("ALTER TABLE {". $table ."} ALTER $field_new SET NOT NULL");

   930   }

   931 

   932   db_drop_field($ret, $table, $field .'_old');

   933 

   934   if (isset($new_keys)) {

   935     _db_create_keys($ret, $table, $new_keys);

   936   }

   937 }

   938 

   939 /**

   940  * @} End of "ingroup schemaapi".

   941  */

   942