From 95212f57e2f2ac0081427f897153b5d92a3de980 Mon Sep 17 00:00:00 2001
From: Michael Bayne <mdb@samskivert.com>
Date: Tue, 28 Apr 2009 06:27:04 +0000
Subject: [PATCH] Added as().

---
 .../com/samskivert/depot/expression/ColumnExp.java     | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/java/com/samskivert/depot/expression/ColumnExp.java b/src/java/com/samskivert/depot/expression/ColumnExp.java
index 64a4fc6..762c876 100644
--- a/src/java/com/samskivert/depot/expression/ColumnExp.java
+++ b/src/java/com/samskivert/depot/expression/ColumnExp.java
@@ -51,6 +51,16 @@ public class ColumnExp
         this.name = field;
     }
 
+    /**
+     * Returns a column expression for the supplied persistent class with the same name as this
+     * expression. This is useful for "casting" a column expression from a parent class to a
+     * derived class.
+     */
+    public ColumnExp as (Class<? extends PersistentRecord> oClass)
+    {
+        return new ColumnExp(oClass, name);
+    }
+
     // from SQLExpression
     public Object accept (ExpressionVisitor<?> builder)
     {