Added ability to set alias for root table of sql query.

src/test/java/com/avaje/tests/query/TestQueryAlias.java

@@ -0,0 +1,35 @@
+package com.avaje.tests.query;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.avaje.ebean.BaseTestCase;
+import com.avaje.ebean.Ebean;
+import com.avaje.ebean.Query;
+import com.avaje.tests.model.basic.CKeyParent;
+import com.avaje.tests.model.basic.ResetBasicData;
+
+public class TestQueryAlias extends BaseTestCase {
+	@Test
+	public void testExists() {
+		ResetBasicData.reset();
+		
+	    Query<CKeyParent> sq = Ebean.createQuery(CKeyParent.class).select("id.oneKey").alias("st0")
+	            .setAutofetch(false).where().query();
+
+	        Query<CKeyParent> pq = Ebean.find(CKeyParent.class).alias("myt0").where().in("id.oneKey", sq).query();
+
+	        pq.findList();
+
+	        String sql = pq.getGeneratedSql();
+	        
+	        System.out.println(sql);
+	        // Without alias command is should be:
+	        // select t0.one_key c0, t0.two_key c1, t0.name c2, t0.version c3, t0.assoc_id c4 from ckey_parent t0 where  (t0.one_key) in (select t0.one_key from ckey_parent t0)
+	        // but with alias command SQL should look like this:
+	        // select myt0.one_key c0, myt0.two_key c1, myt0.name c2, myt0.version c3, myt0.assoc_id c4 from ckey_parent myt0 where  (myt0.one_key) in (select st0.one_key from ckey_parent st0) 
+	        
+	        Assert.assertTrue(sql.indexOf("ckey_parent myt0")>0);
+	        Assert.assertTrue(sql.indexOf("in (select st0.one_key from ckey_parent st0)")>0);
+	}
+}