1 files changed, 55 insertions, 0 deletions
diff --git a/includes/database/pgsql/schema.inc b/includes/database/pgsql/schema.inc
index f467f0af1..c8af719e8 100644
--- a/includes/database/pgsql/schema.inc
+++ b/includes/database/pgsql/schema.inc
@@ -14,6 +14,61 @@
 class DatabaseSchema_pgsql extends DatabaseSchema {
 
   /**
+   * A cache of information about blob columns and sequences of tables.
+   *
+   * This is collected by DatabaseConnection_pgsql->queryTableInformation(),
+   * by introspecting the database.
+   *
+   * @see DatabaseConnection_pgsql->queryTableInformation().
+   * @var array
+   */
+  protected $tableInformation = array();
+
+  /**
+   * Fetch the list of blobs and sequences used on a table.
+   *
+   * We introspect the database to collect the information required by insert
+   * and update queries.
+   *
+   * @param $table_name
+   *   The non-prefixed name of the table.
+   * @return
+   *   An object with two member variables:
+   *     - 'blob_fields' that lists all the blob fields in the table.
+   *     - 'sequences' that lists the sequences used in that table.
+   */
+  public function queryTableInformation($table) {
+    // Generate a key to reference this table's information on.
+    $key = $this->connection->prefixTables('{' . $table . '}');
+    if (!strpos($key, '.')) {
+      $key = 'public.' . $key;
+    }
+
+    if (!isset($this->tableInformation[$key])) {
+      // Split the key into schema and table for querying.
+      list($schema,$table_name) = explode('.', $key);
+      $table_information = (object) array(
+        'blob_fields' => array(),
+        'sequences' => array(),
+      );
+      $result = db_query("SELECT column_name, data_type, column_default FROM information_schema.columns WHERE table_schema = :schema AND table_name = :table AND (data_type = 'bytea' OR (numeric_precision IS NOT NULL AND column_default LIKE :default))", array(':schema' => $schema, ':table' => $table_name, ':default' => '%nextval%'));
+      foreach ($result as $column) {
+        if ($column->data_type == 'bytea') {
+          $table_information->blob_fields[$column->column_name] = TRUE;
+        }
+        else if (preg_match("/nextval\('([^']+)'/", $column->column_default, $matches)) {
+          // We must know of any sequences in the table structure to help us
+          // return the last insert id. If there is more than 1 sequences the
+          // first one (index 0 of the sequences array) will be used.
+          $table_information->sequences[] = $matches[1];
+        }
+      }
+      $this->tableInformation[$key] = $table_information;
+    }
+    return $this->tableInformation[$key];
+  }
+
+  /**
    * Generate SQL to create a new table from a Drupal schema definition.
    *
    * @param $name