3 files changed, 102 insertions, 2 deletions
diff --git a/includes/database/database.inc b/includes/database/database.inc
index 73cb243e5..ca6023f2d 100644
--- a/includes/database/database.inc
+++ b/includes/database/database.inc
@@ -810,6 +810,34 @@ abstract class DatabaseConnection extends PDO {
   }
 
   /**
+   * Escapes an alias name string.
+   *
+   * Force all alias names to be strictly alphanumeric-plus-underscore. In
+   * contrast to DatabaseConnection::escapeField() /
+   * DatabaseConnection::escapeTable(), this doesn't allow the period (".") 
+   *
+   * @return
+   *   The sanitized field name string.
+   */
+  public function escapeAlias($field) {
+    return preg_replace('/[^A-Za-z0-9_]+/', '', $field);
+  }
+
+  /**
+   * Escapes a alias name string.
+   *
+   * Force all alias names to be strictly alphanumeric-plus-underscore. In
+   * contrast to DatabaseConnection::escapeField() /
+   * DatabaseConnection::escapeTable(), this doesn't allow the point.
+   *
+   * @return
+   *   The sanitized field name string.
+   */
+  public function escapeAlias($field) {
+    return preg_replace('/[^A-Za-z0-9_]+/', '', $field);
+  }
+
+  /**
    * Escapes characters that work as wildcard characters in a LIKE pattern.
    *
    * The wildcard characters "%" and "_" as well as backslash are prefixed with
diff --git a/includes/database/pgsql/query.inc b/includes/database/pgsql/query.inc
index 61c821801..7642f53f7 100644
--- a/includes/database/pgsql/query.inc
+++ b/includes/database/pgsql/query.inc
@@ -217,4 +217,71 @@ class SelectQuery_pgsql extends SelectQuery {
     return $this;
   }
 
+  /**
+   * Overrides SelectQuery::orderBy().
+   *
+   * Automatically adds columns that are ordered on as fields.
+   */
+  public function orderBy($field, $direction = 'ASC') {
+    // Call parent function to order on this.
+    $return = parent::orderBy($field, $direction);
+
+    // PostgreSQL requires that when using DISTINCT or GROUP BY conditions,
+    // fields/expressions that are ordered on also need to be selected.
+    // This function tries to automatically add a field if it is not already
+    // added or a condition applies that makes it impossible to handle that
+    // automatically. In such cases, the query might fail on PostgreSQL if the
+    // field or expression is not added manually.
+
+    // If there is a table alias specified, split it up.
+    if (strpos($field, '.') !== FALSE) {
+      list($table, $table_field) = explode('.', $field);
+    }
+    // Figure out if the field has already been added.
+    foreach ($this->fields as $existing_field) {
+      if (!empty($table)) {
+        // If table alias is given, check if field and table exists.
+        if ($existing_field['table'] == $table && $existing_field['field'] == $table_field) {
+          return $return;
+        }
+      }
+      else {
+        // If there is no table, simply check if the field exists as a field or
+        // an aliased field.
+        if ($existing_field['alias'] == $field) {
+          return $return;
+        }
+      }
+    }
+
+    // Also check expression aliases.
+    foreach ($this->expressions as $expression) {
+      if ($expression['alias'] == $field) {
+        return $return;
+      }
+    }
+
+    // If a table loads all fields, it can not be added again. It would
+    // result in an ambigious alias error because that field would be loaded
+    // twice: Once through table_alias.* and once directly. If the field
+    // actually belongs to a different table, it must be added manually.
+    foreach ($this->tables as $table) {
+      if (!empty($table['all_fields'])) {
+        return $return;
+      }
+    }
+
+    // If $field contains an characters which are not allowed in a field name
+    // it is considered an expression, these can't be handeld automatically
+    // either.
+    if ($this->connection->escapeField($field) != $field) {
+      return $return;
+    }
+
+    // This is a case that can be handled automatically, add the field.
+    $this->addField(NULL, $field);
+    return $return;
+  }
+
+
 }
diff --git a/includes/database/select.inc b/includes/database/select.inc
index d46abefdf..0fc17f586 100644
--- a/includes/database/select.inc
+++ b/includes/database/select.inc
@@ -366,6 +366,11 @@ interface SelectQueryInterface extends QueryConditionInterface, QueryAlterableIn
    * If called multiple times, the query will order by each specified field in the
    * order this method is called.
    *
+   * If the query uses DISTINCT or GROUP BY conditions, fields or expressions
+   * that are used for the order must be selected to be compatible with some
+   * databases like PostgreSQL. The PostgreSQL driver can handle simple cases
+   * automatically but it is suggested to explicitly specify them.
+   *
    * @param $field
    *   The field on which to order.
    * @param $direction
@@ -1373,10 +1378,10 @@ class SelectQuery extends Query implements SelectQueryInterface {
     foreach ($this->fields as $alias => $field) {
       // Always use the AS keyword for field aliases, as some
       // databases require it (e.g., PostgreSQL).
-      $fields[] = (isset($field['table']) ? $this->connection->escapeTable($field['table']) . '.' : '') . $this->connection->escapeField($field['field']) . ' AS ' . $this->connection->escapeField($field['alias']);
+      $fields[] = (isset($field['table']) ? $this->connection->escapeTable($field['table']) . '.' : '') . $this->connection->escapeField($field['field']) . ' AS ' . $this->connection->escapeAlias($field['alias']);
     }
     foreach ($this->expressions as $alias => $expression) {
-      $fields[] = $expression['expression'] . ' AS ' . $expression['alias'];
+      $fields[] = $expression['expression'] . ' AS ' . $this->connection->escapeAlias($expression['alias']);
     }
     $query .= implode(', ', $fields);