[rygel] db: Fix exec to run multiple queries at once

[Jens Georg <jensgeorg src gnome org>]

commit 9cc38dbd7c0a4016e8399796f0422c26018b34e7
Author: Jens Georg <mail jensge org>
Date:   Thu Sep 3 22:52:05 2015 +0200

    db: Fix exec to run multiple queries at once
    
    Signed-off-by: Jens Georg <mail jensge org>

 src/librygel-db/database.vala |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)
---
diff --git a/src/librygel-db/database.vala b/src/librygel-db/database.vala
index e931c55..94d915c 100644
--- a/src/librygel-db/database.vala
+++ b/src/librygel-db/database.vala
@@ -195,6 +195,16 @@ public class Rygel.Database.Database : Object {
     public void exec (string        sql,
                       GLib.Value[]? arguments = null)
                       throws DatabaseError {
+        if (arguments == null) {
+            this.db.exec (sql);
+            if (this.db.errcode () != Sqlite.OK) {
+                var msg = "Failed to run query %s: %s";
+                throw new DatabaseError.SQLITE_ERROR (msg, sql, this.db.errmsg ());
+            }
+
+            return;
+        }
+
         var cursor = this.exec_cursor (sql, arguments);
         while (cursor.has_next ()) {
             cursor.next ();