#196862 by Damien Tournoud, et al: Replace COUNT(*) queries with SELECT 1 ... LIMIT 1 queries when all that's required is a check for whether rows exist.

modules/block/block.admin.inc

@@ -272,7 +272,8 @@ function block_admin_configure(&$form_state, $module = NULL, $delta = 0) {
 
 function block_admin_configure_validate($form, &$form_state) {
   if ($form_state['values']['module'] == 'block') {
-    if (empty($form_state['values']['info']) || db_result(db_query("SELECT COUNT(*) FROM {box} WHERE bid <> %d AND info = '%s'", $form_state['values']['delta'], $form_state['values']['info']))) {
+    $box_exists = (bool) db_query_range('SELECT 1 FROM {box} WHERE bid <> :bid AND info = :info', array(':bid' => $form_state['values']['delta'], ':info' => $form_state['values']['info']), 0, 1)->fetchField();
+    if (empty($form_state['values']['info']) || $box_exists) {
       form_set_error('info', t('Please ensure that each block description is unique.'));
     }
   }
@@ -301,7 +302,9 @@ function block_add_block_form(&$form_state) {
 }
 
 function block_add_block_form_validate($form, &$form_state) {
-  if (empty($form_state['values']['info']) || db_result(db_query("SELECT COUNT(*) FROM {box} WHERE info = '%s'", $form_state['values']['info']))) {
+  $box_exists = (bool) db_query_range('SELECT 1 FROM {box} WHERE info = :info', array(':info' => $form_state['values']['info']), 0, 1)->fetchField();
+
+  if (empty($form_state['values']['info']) || $box_exists) {
     form_set_error('info', t('Please ensure that each block description is unique.'));
   }
 }

modules/block/block.module

@@ -494,8 +494,8 @@ function block_system_themes_form_submit(&$form, &$form_state) {
     }
     if ($form_state['values']['admin_theme'] && $form_state['values']['admin_theme'] != variable_get('admin_theme', 0)) {
       // If we're changing themes, make sure the theme has its blocks initialized.
-      $result = db_result(db_query("SELECT COUNT(*) FROM {block} WHERE theme = '%s'", $form_state['values']['admin_theme']));
+      $has_blocks = (bool) db_query_range('SELECT 1 FROM {block} WHERE theme = :theme', array(':theme' => $form_state['values']['admin_theme']), 0, 1)->fetchField();
-      if (!$result) {
+      if (!$has_blocks) {
         block_initialize_theme_blocks($form_state['values']['admin_theme']);
       }
     }
@@ -515,7 +515,8 @@ function block_system_themes_form_submit(&$form, &$form_state) {
  */
 function block_initialize_theme_blocks($theme) {
   // Initialize theme's blocks if none already registered.
-  if (!(db_result(db_query("SELECT COUNT(*) FROM {block} WHERE theme = '%s'", $theme)))) {
+  $has_blocks = (bool) db_query_range('SELECT 1 FROM {block} WHERE theme = :theme', array(':theme' => $theme), 0, 1)->fetchField();
+  if (!$has_blocks) {
     $default_theme = variable_get('theme_default', 'garland');
     $regions = system_region_list($theme);
     $result = db_query("SELECT * FROM {block} WHERE theme = '%s'", $default_theme);

modules/node/node.module

@@ -555,7 +555,7 @@ function node_types_rebuild() {
 function node_type_save($info) {
   $is_existing = FALSE;
   $existing_type = !empty($info->old_type) ? $info->old_type : $info->type;
-  $is_existing = db_query("SELECT COUNT(*) FROM {node_type} WHERE type = :type", array(':type' => $existing_type))->fetchField();
+  $is_existing = (bool) db_query_range('SELECT 1 FROM {node_type} WHERE type = :type', array(':type' => $existing_type), 0, 1)->fetchField();
   $type = node_type_set_defaults($info);
 
   $fields = array(
@@ -3085,8 +3085,8 @@ function node_assign_owner_action_form($context) {
 }
 
 function node_assign_owner_action_validate($form, $form_state) {
-  $count = db_query('SELECT COUNT(*) FROM {users} WHERE name = :name', array(':name' => $form_state['values']['owner_name']))->fetchField();
+  $exists = (bool) db_query_range('SELECT 1 FROM {users} WHERE name = :name', array(':name' => $form_state['values']['owner_name']), 0, 1)->fetchField();
-  if (intval($count) != 1) {
+  if (!$exists) {
     form_set_error('owner_name', t('Please enter a valid username.'));
   }
 }

modules/path/path.admin.inc

@@ -15,8 +15,8 @@ function path_admin_overview($keys = NULL) {
   // Add the filter form above the overview table.
   $output = drupal_get_form('path_admin_filter_form', $keys);
   // Enable language column if locale is enabled or if we have any alias with language
-  $count = db_query("SELECT COUNT(*) FROM {url_alias} WHERE language <> ''")->fetchField();
+  $alias_exists = (bool) db_query_range('SELECT 1 FROM {url_alias} WHERE language <> :language', array(':language' => ''), 0, 1)->fetchField();
-  $multilanguage = (module_exists('locale') || $count);
+  $multilanguage = (module_exists('locale') || $alias_exists);
 
   $header = array(
     array('data' => t('Alias'), 'field' => 'dst', 'sort' => 'asc'),

modules/php/php.install

@@ -10,7 +10,7 @@
  * Implementation of hook_install().
  */
 function php_install() {
-  $format_exists = db_query("SELECT COUNT(*) FROM {filter_format} WHERE name = 'PHP code'")->fetchField();
+  $format_exists = (bool) db_query_range('SELECT 1 FROM {filter_format} WHERE name = :name', array(':name' => 'PHP code'), 0, 1)->fetchField();
   // Add a PHP code text format, if it does not exist. Do this only for the
   // first install (or if the format has been manually deleted) as there is no
   // reliable method to identify the format in an uninstall hook or in

modules/profile/profile.module

@@ -511,7 +511,8 @@ function profile_category_access($account, $category) {
     return TRUE;
   }
   else {
-    return user_edit_access($account) && db_result(db_query("SELECT COUNT(*) FROM {profile_field} WHERE category = '%s' AND visibility <> %d", $category, PROFILE_HIDDEN));
+    $category_visible = (bool) db_query_range('SELECT 1 FROM {profile_field} WHERE category = :category AND visibility <> :visibility', array(':category' => $category, ':visibility' => PROFILE_HIDDEN), 0, 1)->fetchField();
+    return user_edit_access($account) && $category_visible;
   }
 }
 

modules/profile/profile.pages.inc

@@ -110,7 +110,8 @@ function profile_browse() {
  */
 function profile_autocomplete($field, $string) {
   $matches = array();
-  if (db_result(db_query("SELECT COUNT(*) FROM {profile_field} WHERE fid = %d AND autocomplete = 1", $field))) {
+  $autocomplete_field = (bool) db_query_range("SELECT 1 FROM {profile_field} WHERE fid = :fid AND autocomplete = 1", array(':fid' => $field), 0, 1)->fetchField();
+  if ($autocomplete_field) {
     $result = db_query_range("SELECT value FROM {profile_value} WHERE fid = :fid AND LOWER(value) LIKE LOWER(:value) GROUP BY value ORDER BY value ASC", array(
       ':fid' => $field,
       ':value' => $string .'%',

modules/system/system.api.php

@@ -1199,8 +1199,8 @@ function hook_file_move($file, $source) {
  */
 function hook_file_references($file) {
   // If upload.module is still using a file, do not let other modules delete it.
-  $count = db_query('SELECT COUNT(*) FROM {upload} WHERE fid = :fid', array(':fid' => $file->fid))->fetchField();
+  $file_used = (bool) db_query_range('SELECT 1 FROM {upload} WHERE fid = :fid', array(':fid' => $file->fid), 0, 1)->fetchField();
-  if ($count) {
+  if ($file_used) {
     // Return the name of the module and how many references it has to the file.
     return array('upload' => $count);
   }

modules/upload/upload.module

@@ -282,8 +282,8 @@ function upload_file_load($files) {
  */
 function upload_file_references($file) {
   // If upload.module is still using a file, do not let other modules delete it.
-  $count = db_query('SELECT COUNT(*) FROM {upload} WHERE fid = :fid', array(':fid' => $file->fid))->fetchField();
+  $file_used = (bool) db_query_range('SELECT 1 FROM {upload} WHERE fid = :fid', array(':fid' => $file->fid), 0, 1)->fetchField();
-  if ($count) {
+  if ($file_used) {
     // Return the name of the module and how many references it has to the file.
     return array('upload' => $count);
   }

modules/user/user.admin.inc

@@ -731,16 +731,13 @@ function user_admin_role() {
 function user_admin_role_validate($form, &$form_state) {
   if ($form_state['values']['name']) {
     if ($form_state['values']['op'] == t('Save role')) {
-      $existing_role = db_query("SELECT COUNT(*) FROM {role} WHERE name = :name AND rid != :rid",
+      $existing_role = (bool) db_query_range("SELECT 1 FROM {role} WHERE name = :name AND rid != :rid", array(':name' => $form_state['values']['name'], ':rid' => $form_state['values']['rid']), 0, 1)->fetchField();
-                                array(':name' => $form_state['values']['name'],
-                                      ':rid' => $form_state['values']['rid']))
-                       ->fetchField();
       if ($existing_role) {
         form_set_error('name', t('The role name %name already exists. Please choose another role name.', array('%name' => $form_state['values']['name'])));
       }
     }
     elseif ($form_state['values']['op'] == t('Add role')) {
-      if (db_query("SELECT COUNT(*) FROM {role} WHERE name = :name", array(':name' => $form_state['values']['name']))->fetchField()) {
+      if ((bool) db_query_range('SELECT 1 FROM {role} WHERE name = :name', array(':name' => $form_state['values']['name']), 0, 1)->fetchField()) {
         form_set_error('name', t('The role name %name already exists. Please choose another role name.', array('%name' => $form_state['values']['name'])));
       }
     }

modules/user/user.module

@@ -822,8 +822,8 @@ function user_file_download($filepath) {
  */
 function user_file_references($file) {
   // Determine if the file is used by this module.
-  $count = db_query('SELECT COUNT(*) FROM {users} WHERE picture = :fid', array(':fid' => $file->fid))->fetchField();
+  $file_used = (bool) db_query_range('SELECT 1 FROM {users} WHERE picture = :fid', array(':fid' => $file->fid), 0, 1)->fetchField();
-  if ($count) {
+  if ($file_used) {
     // Return the name of the module and how many references it has to the file.
     return array('user' => $count);
   }
@@ -935,7 +935,7 @@ function user_user_validate(&$edit, &$account, $category = NULL) {
       if ($error = user_validate_name($edit['name'])) {
         form_set_error('name', $error);
       }
-      elseif (db_query("SELECT COUNT(*) FROM {users} WHERE uid != :uid AND LOWER(name) = LOWER(:name)", array(':uid' => $uid, ':name' => $edit['name']))->fetchField() > 0) {
+      elseif ((bool) db_query_range("SELECT 1 FROM {users} WHERE uid != :uid AND LOWER(name) = LOWER(:name)", array(':uid' => $uid, ':name' => $edit['name']), 0, 1)->fetchField()) {
         form_set_error('name', t('The name %name is already taken.', array('%name' => $edit['name'])));
       }
     }
@@ -944,7 +944,7 @@ function user_user_validate(&$edit, &$account, $category = NULL) {
     if ($error = user_validate_mail($edit['mail'])) {
       form_set_error('mail', $error);
     }
-    elseif (db_query("SELECT COUNT(*) FROM {users} WHERE uid != :uid AND LOWER(mail) = LOWER(:mail)", array(':uid' => $uid, ':mail' => $edit['mail']))->fetchField() > 0) {
+    elseif ((bool) db_query_range("SELECT 1 FROM {users} WHERE uid != :uid AND LOWER(mail) = LOWER(:mail)", array(':uid' => $uid, ':mail' => $edit['mail']), 0, 1)->fetchField()) {
       // Format error message dependent on whether the user is logged in or not.
       if ($GLOBALS['user']->uid) {
         form_set_error('mail', t('The e-mail address %email is already taken.', array('%email' => $edit['mail'])));