database.mysql.inc 11.3 KB
Newer Older
Dries's avatar
   
Dries committed
1
<?php
Kjartan's avatar
Kjartan committed
2
// $Id$
Dries's avatar
   
Dries committed
3

Dries's avatar
   
Dries committed
4
5
6
7
8
9
/**
 * @file
 * Database interface code for MySQL database servers.
 */

/**
Dries's avatar
   
Dries committed
10
 * @ingroup database
Dries's avatar
   
Dries committed
11
12
13
14
15
16
17
18
19
20
21
22
 * @{
 */

/**
 * Initialize a database connection.
 *
 * Note that you can change the mysql_connect() call to mysql_pconnect() if you
 * want to use persistent connections. This is not recommended on shared hosts,
 * and might require additional database/webserver tuning. It can increase
 * performance, however, when the overhead to connect to your database is high
 * (e.g. your database and web server live on different machines).
 */
Dries's avatar
   
Dries committed
23
function db_connect($url) {
24
25
26
27
28
29
30
31
32
  // Check if MySQL support is present in PHP
  if (!function_exists('mysql_connect')) {
    drupal_maintenance_theme();
    drupal_set_title('PHP MySQL support not enabled');
    print theme('maintenance_page', '<p>We were unable to use the MySQL database because the MySQL extension for PHP is not installed. Check your <code>PHP.ini</code> to see how you can enable it.</p>
<p>For more help, see the <a href="http://drupal.org/node/258">Installation and upgrading handbook</a>. If you are unsure what these terms mean you should probably contact your hosting provider.</p>');
    exit;
  }

Dries's avatar
   
Dries committed
33
34
  $url = parse_url($url);

35
  // Allow for non-standard MySQL port.
Dries's avatar
   
Dries committed
36
37
  if (isset($url['port'])) {
     $url['host'] = $url['host'] .':'. $url['port'];
38
  }
Dries's avatar
   
Dries committed
39

40
41
42
43
44
45
  // - TRUE makes mysql_connect() always open a new link, even if
  //   mysql_connect() was called before with the same parameters.
  //   This is important if you are using two databases on the same
  //   server.
  // - 2 means CLIENT_FOUND_ROWS: return the number of found
  //   (matched) rows, not the number of affected rows.
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
  $connection = @mysql_connect($url['host'], $url['user'], $url['pass'], TRUE, 2);
  if (!$connection) {
    drupal_maintenance_theme();
    drupal_set_title('Unable to connect to database server');
    print theme('maintenance_page', '<p>This either means that the username and password information in your <code>settings.php</code> file is incorrect or we can\'t contact the MySQL database server. This could mean your hosting provider\'s database server is down.</p>
<p>The MySQL error was: '. theme('placeholder', mysql_error()) .'.</p>
<p>Currently, the username is '. theme('placeholder', $url['user']) .' and the database server is '. theme('placeholder', $url['host']) .'.</p>
<ul>
  <li>Are you sure you have the correct username and password?</li>
  <li>Are you sure that you have typed the correct hostname?</li>
  <li>Are you sure that the database server is running?</li>
</ul>
<p>For more help, see the <a href="http://drupal.org/node/258">Installation and upgrading handbook</a>. If you are unsure what these terms mean you should probably contact your hosting provider.</p>');
    exit;
  }
61

62
63
64
65
66
67
68
69
70
71
72
73
74
75
  if (!mysql_select_db(substr($url['path'], 1))) {
    drupal_maintenance_theme();
    drupal_set_title('Unable to select database');
    print theme('maintenance_page', '<p>We were able to connect to the MySQL database server (which means your username and password is okay) but not able to select the database.</p>
<p>The MySQL error was: '. theme('placeholder', mysql_error()) .'.</p>
<p>Currently, the database is '. theme('placeholder', substr($url['path'], 1)) .'. The username is '. theme('placeholder', $url['user']) .' and the database server is '. theme('placeholder', $url['host']) .'.</p>
<ul>
  <li>Are you sure you have the correct database name?</li>
  <li>Are you sure the database exists?</li>
  <li>Are you sure the username has permission to access the database?</li>
</ul>
<p>For more help, see the <a href="http://drupal.org/node/258">Installation and upgrading handbook</a>. If you are unsure what these terms mean you should probably contact your hosting provider.</p>');
    exit;
  }
Dries's avatar
   
Dries committed
76

Dries's avatar
   
Dries committed
77
  return $connection;
Dries's avatar
   
Dries committed
78
79
}

Dries's avatar
   
Dries committed
80
81
82
/**
 * Helper function for db_query().
 */
Dries's avatar
   
Dries committed
83
function _db_query($query, $debug = 0) {
84
  global $active_db, $queries;
Dries's avatar
   
Dries committed
85

86
  if (variable_get('dev_query', 0)) {
Dries's avatar
   
Dries committed
87
    list($usec, $sec) = explode(' ', microtime());
Dries's avatar
   
Dries committed
88
    $timer = (float)$usec + (float)$sec;
Dries's avatar
   
Dries committed
89
  }
Dries's avatar
   
Dries committed
90

Dries's avatar
   
Dries committed
91
  $result = mysql_query($query, $active_db);
Dries's avatar
   
Dries committed
92

93
  if (variable_get('dev_query', 0)) {
Dries's avatar
   
Dries committed
94
    list($usec, $sec) = explode(' ', microtime());
Dries's avatar
   
Dries committed
95
96
97
98
99
    $stop = (float)$usec + (float)$sec;
    $diff = $stop - $timer;
    $queries[] = array($query, $diff);
  }

Dries's avatar
   
Dries committed
100
  if ($debug) {
Dries's avatar
   
Dries committed
101
    print '<p>query: '. $query .'<br />error:'. mysql_error() .'</p>';
Dries's avatar
   
Dries committed
102
103
  }

Dries's avatar
   
Dries committed
104
  if (!mysql_errno()) {
Dries's avatar
   
Dries committed
105
    return $result;
Kjartan's avatar
Kjartan committed
106
107
  }
  else {
Dries's avatar
Dries committed
108
    trigger_error(check_plain(mysql_error() ."\nquery: ". $query), E_USER_ERROR);
109
    return FALSE;
Dries's avatar
   
Dries committed
110
111
112
  }
}

Dries's avatar
   
Dries committed
113
114
115
116
117
118
119
120
121
/**
 * Fetch one result row from the previous query as an object.
 *
 * @param $result
 *   A database query result resource, as returned from db_query().
 * @return
 *   An object representing the next row of the result. The attributes of this
 *   object are the table fields selected by the query.
 */
Dries's avatar
   
Dries committed
122
123
124
125
126
127
function db_fetch_object($result) {
  if ($result) {
    return mysql_fetch_object($result);
  }
}

Dries's avatar
   
Dries committed
128
129
130
131
132
133
134
135
136
137
/**
 * Fetch one result row from the previous query as an array.
 *
 * @param $result
 *   A database query result resource, as returned from db_query().
 * @return
 *   An associative array representing the next row of the result. The keys of
 *   this object are the names of the table fields selected by the query, and
 *   the values are the field values for this result row.
 */
Dries's avatar
   
Dries committed
138
139
140
141
142
143
function db_fetch_array($result) {
  if ($result) {
    return mysql_fetch_array($result, MYSQL_ASSOC);
  }
}

Dries's avatar
   
Dries committed
144
145
146
147
148
149
150
151
/**
 * Determine how many result rows were found by the preceding query.
 *
 * @param $result
 *   A database query result resource, as returned from db_query().
 * @return
 *   The number of result rows.
 */
Dries's avatar
   
Dries committed
152
153
154
155
156
157
function db_num_rows($result) {
  if ($result) {
    return mysql_num_rows($result);
  }
}

Dries's avatar
   
Dries committed
158
159
160
161
162
163
164
165
166
167
168
169
170
/**
 * Return an individual result field from the previous query.
 *
 * Only use this function if exactly one field is being selected; otherwise,
 * use db_fetch_object() or db_fetch_array().
 *
 * @param $result
 *   A database query result resource, as returned from db_query().
 * @param $row
 *   The index of the row whose result is needed.
 * @return
 *   The resulting field.
 */
Dries's avatar
   
Dries committed
171
172
173
174
175
176
function db_result($result, $row = 0) {
  if ($result && mysql_num_rows($result) > $row) {
    return mysql_result($result, $row);
  }
}

Dries's avatar
   
Dries committed
177
178
179
/**
 * Determine whether the previous query caused an error.
 */
Dries's avatar
   
Dries committed
180
181
182
183
function db_error() {
  return mysql_errno();
}

Dries's avatar
   
Dries committed
184
185
186
187
188
189
190
191
/**
 * Return a new unique ID in the given sequence.
 *
 * For compatibility reasons, Drupal does not use auto-numbered fields in its
 * database tables. Instead, this function is used to return a new unique ID
 * of the type requested. If necessary, a new sequence with the given name
 * will be created.
 */
Dries's avatar
   
Dries committed
192
function db_next_id($name) {
Dries's avatar
   
Dries committed
193
  $name = db_prefix_tables($name);
Dries's avatar
   
Dries committed
194
  db_query('LOCK TABLES {sequences} WRITE');
Dries's avatar
   
Dries committed
195
196
  $id = db_result(db_query("SELECT id FROM {sequences} WHERE name = '%s'", $name)) + 1;
  db_query("REPLACE INTO {sequences} VALUES ('%s', %d)", $name, $id);
Dries's avatar
   
Dries committed
197
  db_query('UNLOCK TABLES');
Dries's avatar
   
Dries committed
198
199
200
201

  return $id;
}

Dries's avatar
   
Dries committed
202
203
204
/**
 * Determine the number of rows changed by the preceding query.
 */
Dries's avatar
   
Dries committed
205
206
207
208
function db_affected_rows() {
  return mysql_affected_rows();
}

Dries's avatar
   
Dries committed
209
/**
Dries's avatar
   
Dries committed
210
211
212
213
214
215
 * Runs a limited-range query in the active database.
 *
 * Use this as a substitute for db_query() when a subset of the query is to be
 * returned.
 * User-supplied arguments to the query should be passed in as separate parameters
 * so that they can be properly escaped to avoid SQL injection attacks.
Dries's avatar
   
Dries committed
216
 *
217
218
219
220
221
 * Note that if you need to know how many results were returned, you should do
 * a SELECT COUNT(*) on the temporary table afterwards. db_num_rows() and
 * db_affected_rows() do not give consistent result across different database
 * types in this case.
 *
Dries's avatar
   
Dries committed
222
223
224
 * @param $query
 *   A string containing an SQL query.
 * @param ...
225
226
227
228
229
230
231
232
233
 *   A variable number of arguments which are substituted into the query
 *   using printf() syntax. The query arguments can be enclosed in one
 *   array instead.
 *   Valid %-modifiers are: %s, %d, %f, %b (binary data, do not enclose
 *   in '') and %%.
 *
 *   NOTE: using this syntax will cast NULL and FALSE values to decimal 0,
 *   and TRUE values to decimal 1.
 *
Dries's avatar
   
Dries committed
234
235
236
237
238
239
240
 * @param $from
 *   The first result row to return.
 * @param $count
 *   The maximum number of result rows to return.
 * @return
 *   A database query result resource, or FALSE if the query was not executed
 *   correctly.
Dries's avatar
   
Dries committed
241
 */
Dries's avatar
Dries committed
242
243
244
245
function db_query_range($query) {
  $args = func_get_args();
  $count = array_pop($args);
  $from = array_pop($args);
246
  array_shift($args);
247
248

  $query = db_prefix_tables($query);
249
250
  if (isset($args[0]) and is_array($args[0])) { // 'All arguments in one array' syntax
    $args = $args[0];
Dries's avatar
Dries committed
251
  }
252
253
  _db_query_callback($args, TRUE);
  $query = preg_replace_callback(DB_QUERY_REGEXP, '_db_query_callback', $query);
Dries's avatar
   
Dries committed
254
  $query .= ' LIMIT '. $from .', '. $count;
Dries's avatar
Dries committed
255
  return _db_query($query);
Dries's avatar
   
Dries committed
256
257
}

258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
/**
 * Runs a SELECT query and stores its results in a temporary table.
 *
 * Use this as a substitute for db_query() when the results need to stored
 * in a temporary table. Temporary tables exist for the duration of the page
 * request.
 * User-supplied arguments to the query should be passed in as separate parameters
 * so that they can be properly escaped to avoid SQL injection attacks.
 *
 * Note that if you need to know how many results were returned, you should do
 * a SELECT COUNT(*) on the temporary table afterwards. db_num_rows() and
 * db_affected_rows() do not give consistent result across different database
 * types in this case.
 *
 * @param $query
 *   A string containing a normal SELECT SQL query.
 * @param ...
275
276
277
278
279
280
281
282
283
 *   A variable number of arguments which are substituted into the query
 *   using printf() syntax. The query arguments can be enclosed in one
 *   array instead.
 *   Valid %-modifiers are: %s, %d, %f, %b (binary data, do not enclose
 *   in '') and %%.
 *
 *   NOTE: using this syntax will cast NULL and FALSE values to decimal 0,
 *   and TRUE values to decimal 1.
 *
284
 * @param $table
285
286
 *   The name of the temporary table to select into. This name will not be
 *   prefixed as there is no risk of collision.
287
288
289
290
291
292
293
 * @return
 *   A database query result resource, or FALSE if the query was not executed
 *   correctly.
 */
function db_query_temporary($query) {
  $args = func_get_args();
  $tablename = array_pop($args);
294
  array_shift($args);
295

296
  $query = preg_replace('/^SELECT/i', 'CREATE TEMPORARY TABLE '. $tablename .' SELECT', db_prefix_tables($query));
297
298
  if (isset($args[0]) and is_array($args[0])) { // 'All arguments in one array' syntax
    $args = $args[0];
299
  }
300
301
  _db_query_callback($args, TRUE);
  $query = preg_replace_callback(DB_QUERY_REGEXP, '_db_query_callback', $query);
302
303
304
  return _db_query($query);
}

Dries's avatar
   
Dries committed
305
306
307
308
309
310
311
312
313
/**
 * Returns a properly formatted Binary Large OBject value.
 *
 * @param $data
 *   Data to encode.
 * @return
 *  Encoded data.
 */
function db_encode_blob($data) {
314
  return "'" . mysql_real_escape_string($data) . "'";
Dries's avatar
   
Dries committed
315
316
317
}

/**
318
 * Returns text from a Binary Large Object value.
Dries's avatar
   
Dries committed
319
320
321
322
323
324
325
326
327
328
 *
 * @param $data
 *   Data to decode.
 * @return
 *  Decoded data.
 */
function db_decode_blob($data) {
  return $data;
}

Dries's avatar
   
Dries committed
329
330
331
332
/**
 * Prepare user input for use in a database query, preventing SQL injection attacks.
 */
function db_escape_string($text) {
333
  return mysql_real_escape_string($text);
Dries's avatar
   
Dries committed
334
335
}

336
337
338
339
340
341
342
343
344
345
346
347
348
349
/**
 * Lock a table.
 */
function db_lock_table($table) {
  db_query('LOCK TABLES {%s} WRITE', $table);
}

/**
 * Unlock all locked tables.
 */
function db_unlock_tables() {
  db_query('UNLOCK TABLES');
}

Dries's avatar
   
Dries committed
350
/**
Dries's avatar
   
Dries committed
351
 * @} End of "ingroup database".
Dries's avatar
   
Dries committed
352
353
 */

354