From 1a7bac90e75ad36ea5d9c3e97baeddd87435ed52 Mon Sep 17 00:00:00 2001
From: Neil Drumm <drumm@3064.no-reply.drupal.org>
Date: Mon, 23 Oct 2006 18:38:45 +0000
Subject: [PATCH] #76819 by smsimms and sammys. Move part of the sql rewriting
down into the database abstraction layer and add extra rewriting needed only
for Postgres.
---
includes/database.inc | 4 +---
includes/database.mysql.inc | 17 +++++++++++++++++
includes/database.mysqli.inc | 17 +++++++++++++++++
includes/database.pgsql.inc | 19 +++++++++++++++++++
4 files changed, 54 insertions(+), 3 deletions(-)
diff --git a/includes/database.inc b/includes/database.inc
index 3cb55d06b037..26e59619d637 100644
--- a/includes/database.inc
+++ b/includes/database.inc
@@ -261,9 +261,7 @@ function db_rewrite_sql($query, $primary_table = 'n', $primary_field = 'nid', $
list($join, $where, $distinct) = _db_rewrite_sql($query, $primary_table, $primary_field, $args);
if ($distinct) {
- $field_to_select = 'DISTINCT('. $primary_table .'.'. $primary_field .')';
- // (?<!text) is a negative look-behind (no need to rewrite queries that already use DISTINCT).
- $query = preg_replace('/(SELECT.*)('. $primary_table .'\.)?(?<!DISTINCT\()(?<!DISTINCT\('. $primary_table .'\.)'. $primary_field .'(.*FROM )/AUsi', '\1'. $field_to_select .'\3', $query);
+ $query = db_distinct_field($primary_table, $primary_field, $query);
}
if (!empty($where) || !empty($join)) {
diff --git a/includes/database.mysql.inc b/includes/database.mysql.inc
index b0ffd2692b7a..18eeee019e9a 100644
--- a/includes/database.mysql.inc
+++ b/includes/database.mysql.inc
@@ -417,6 +417,23 @@ function db_table_exists($table) {
return db_num_rows(db_query("SHOW TABLES LIKE '{" . db_escape_table($table) . "}'"));
}
+/**
+ * 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('. $table .'.'. $field .')';
+ // (?<!text) is a negative look-behind (no need to rewrite queries that already use DISTINCT).
+ return preg_replace('/(SELECT.*)('. $table .'\.)?(?<!DISTINCT\()(?<!DISTINCT\('. $table .'\.)'. $field .'(.*FROM )/AUsi', '\1'. $field_to_select .'\3', $query);
+}
+
/**
* @} End of "ingroup database".
*/
diff --git a/includes/database.mysqli.inc b/includes/database.mysqli.inc
index 7cc5943b70b5..7e9ba9dcb5b5 100644
--- a/includes/database.mysqli.inc
+++ b/includes/database.mysqli.inc
@@ -412,6 +412,23 @@ function db_table_exists($table) {
return db_num_rows(db_query("SHOW TABLES LIKE '{" . db_escape_table($table) . "}'"));
}
+/**
+ * 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('. $table .'.'. $field .')';
+ // (?<!text) is a negative look-behind (no need to rewrite queries that already use DISTINCT).
+ return preg_replace('/(SELECT.*)('. $table .'\.)?(?<!DISTINCT\()(?<!DISTINCT\('. $table .'\.)'. $field .'(.*FROM )/AUsi', '\1'. $field_to_select .'\3', $query);
+}
+
/**
* @} End of "ingroup database".
*/
diff --git a/includes/database.pgsql.inc b/includes/database.pgsql.inc
index b5b53b9551c2..14a9a5025183 100644
--- a/includes/database.pgsql.inc
+++ b/includes/database.pgsql.inc
@@ -400,6 +400,25 @@ 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".
*/
--
GitLab