diff options
Diffstat (limited to 'includes/database.pgsql.inc')
| -rw-r--r-- | includes/database.pgsql.inc | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/includes/database.pgsql.inc b/includes/database.pgsql.inc index b5b53b955..14a9a5025 100644 --- a/includes/database.pgsql.inc +++ b/includes/database.pgsql.inc @@ -401,6 +401,25 @@ function db_check_setup() { } /** + * Wraps the given table.field entry with a DISTINCT(). The wrapper is added to + * the SELECT list entry of the given query and the resulting query is returned. + * This function only applies the wrapper if a DISTINCT doesn't already exist in + * the query. + * + * @param $table Table containing the field to set as DISTINCT + * @param $field Field to set as DISTINCT + * @param $query Query to apply the wrapper to + * @return SQL query with the DISTINCT wrapper surrounding the given table.field. + */ +function db_distinct_field($table, $field, $query) { + $field_to_select = 'DISTINCT ON ('. $table .'.'. $field .") $table.$field"; + // (?<!text) is a negative look-behind (no need to rewrite queries that already use DISTINCT). + $query = preg_replace('/(SELECT.*)('. $table .'\.)?(?<!DISTINCT\()(?<!DISTINCT\('. $table .'\.)'. $field .'(.*FROM )/AUsi', '\1'. $field_to_select .'\3', $query); + $query = preg_replace('/(ORDER BY )(?!'.$table.'\.'.$field.')/', '\1'."$table.$field, ", $query); + return $query; +} + +/** * @} End of "ingroup database". */ |