- Patch #793604 by matt2000, chx: DBTNG JOINs are close to useless.

2 files changed, 33 insertions, 5 deletions

diff --git a/includes/database/select.inc b/includes/database/select.inc
index 3e7d27762..ddb78c69d 100644
--- a/includes/database/select.inc
+++ b/includes/database/select.inc
@@ -232,7 +232,9 @@ interface SelectQueryInterface extends QueryConditionInterface, QueryAlterableIn
    *   this clause should use a named placeholder and the value or values to
    *   insert should be passed in the 4th parameter. For the first table joined
    *   on a query, this value is ignored as the first table is taken as the base
-   *   table.
+   *   table. The token %alias can be used in this string to be replaced with
+   *   the actual alias. This is useful when $alias is modified by the database
+   *   system, for example, when joining the same table more than once.
    * @param $arguments
    *   An array of arguments to replace into the $condition of this join.
    * @return
@@ -253,7 +255,9 @@ interface SelectQueryInterface extends QueryConditionInterface, QueryAlterableIn
    *   this clause should use a named placeholder and the value or values to
    *   insert should be passed in the 4th parameter. For the first table joined
    *   on a query, this value is ignored as the first table is taken as the base
-   *   table.
+   *   table. The token %alias can be used in this string to be replaced with
+   *   the actual alias. This is useful when $alias is modified by the database
+   *   system, for example, when joining the same table more than once.
    * @param $arguments
    *   An array of arguments to replace into the $condition of this join.
    * @return
@@ -274,7 +278,9 @@ interface SelectQueryInterface extends QueryConditionInterface, QueryAlterableIn
    *   this clause should use a named placeholder and the value or values to
    *   insert should be passed in the 4th parameter. For the first table joined
    *   on a query, this value is ignored as the first table is taken as the base
-   *   table.
+   *   table. The token %alias can be used in this string to be replaced with
+   *   the actual alias. This is useful when $alias is modified by the database
+   *   system, for example, when joining the same table more than once.
    * @param $arguments
    *   An array of arguments to replace into the $condition of this join.
    * @return
@@ -295,7 +301,9 @@ interface SelectQueryInterface extends QueryConditionInterface, QueryAlterableIn
    *   this clause should use a named placeholder and the value or values to
    *   insert should be passed in the 4th parameter. For the first table joined
    *   on a query, this value is ignored as the first table is taken as the base
-   *   table.
+   *   table. The token %alias can be used in this string to be replaced with
+   *   the actual alias. This is useful when $alias is modified by the database
+   *   system, for example, when joining the same table more than once.
    * @param $arguments
    *   An array of arguments to replace into the $condition of this join.
    * @return
@@ -324,7 +332,9 @@ interface SelectQueryInterface extends QueryConditionInterface, QueryAlterableIn
    *   this clause should use a named placeholder and the value or values to
    *   insert should be passed in the 4th parameter. For the first table joined
    *   on a query, this value is ignored as the first table is taken as the base
-   *   table.
+   *   table. The token %alias can be used in this string to be replaced with
+   *   the actual alias. This is useful when $alias is modified by the database
+   *   system, for example, when joining the same table more than once.
    * @param $arguments
    *   An array of arguments to replace into the $condition of this join.
    * @return
@@ -1210,6 +1220,10 @@ class SelectQuery extends Query implements SelectQueryInterface {
     }
     $alias = $alias_candidate;
 
+    if (is_string($condition)) {
+      $condition = str_replace('%alias', $alias, $condition);
+    }
+
     $this->tables[$alias] = array(
       'join type' => $type,
       'table' => $table,
diff --git a/modules/simpletest/tests/database_test.test b/modules/simpletest/tests/database_test.test
index 064ed3890..dd3f41850 100644
--- a/modules/simpletest/tests/database_test.test
+++ b/modules/simpletest/tests/database_test.test
@@ -1972,6 +1972,20 @@ class DatabaseSelectComplexTestCase extends DatabaseTestCase {
     $job = $query->execute()->fetchField();
     $this->assertEqual($job, 'Songwriter', t('Correct data retrieved.'));
   }
+
+  /**
+   * Confirm we can join on a single table twice with a dynamic alias.
+   */
+  function testJoinTwice() {
+    $query = db_select('test')->fields('test');
+    $alias = $query->join('test', 'test', 'test.job = %alias.job');
+    $query->addField($alias, 'name', 'othername');
+    $query->addField($alias, 'job', 'otherjob');
+    $query->where("$alias.name <> test.name");
+    $crowded_job = $query->execute()->fetch();
+    $this->assertEqual($crowded_job->job, $crowded_job->otherjob, t('Correctly joined same table twice.'));
+    $this->assertNotEqual($crowded_job->name, $crowded_job->othername, t('Correctly joined same table twice.'));
+  }
 }
 
 class DatabaseSelectPagerDefaultTestCase extends DatabaseTestCase {