CountRecord is widely useful. Let's have Depot provide it.

src/java/com/samskivert/depot/CountRecord.java

@@ -0,0 +1,46 @@
+//
+// $Id$
+//
+// Depot library - a Java relational persistence library
+// Copyright (C) 2006-2009 Michael Bayne and Pär Winzell
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.samskivert.depot;
+
+import com.samskivert.depot.annotation.Computed;
+import com.samskivert.depot.annotation.Entity;
+import com.samskivert.depot.expression.ColumnExp;
+
+/**
+ * Handy record for computing the count of something. For example:
+ * <pre>
+ * return load(CountRecord.class,
+ *     new FromOverride(ForumThreadRecord.class),
+ *     new Where(ForumThreadRecord.GROUP_ID.eq(groupId)).count;
+ * </pre>
+ */
+@Computed @Entity
+public class CountRecord extends PersistentRecord
+{
+    // AUTO-GENERATED: FIELDS START
+    public static final Class<CountRecord> _R = CountRecord.class;
+    public static final ColumnExp COUNT = colexp(_R, "count");
+    // AUTO-GENERATED: FIELDS END
+
+    /** The computed count. */
+    @Computed(fieldDefinition="count(*)")
+    public int count;
+}