Order by random. Probably this isn't very optimal.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@2096 6335cc39-0255-0410-8fd6-9bcaacd3b74c

src/java/com/samskivert/jdbc/depot/clause/OrderBy.java

@@ -25,6 +25,7 @@ import java.sql.SQLException;
 
 import com.samskivert.jdbc.depot.ConstructedQuery;
 import com.samskivert.jdbc.depot.expression.ColumnExp;
+import com.samskivert.jdbc.depot.expression.LiteralExp;
 import com.samskivert.jdbc.depot.expression.SQLExpression;
 
 /**
@@ -35,6 +36,14 @@ public class OrderBy extends QueryClause
     /** Indicates the order of the clause. */
     public enum Order { ASC, DESC };
 
+    /**
+     * Creates and returns a random order by clause.
+     */
+    public static OrderBy random ()
+    {
+        return ascending(new LiteralExp("rand()"));
+    }
+
     /**
      * Creates and returns an ascending order by clause on the supplied column.
      */