Added SQL command "EXISTS" and "NOT EXISTS" to Ebean (ExpressionFactory,

ExpressionList).

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

@@ -0,0 +1,41 @@
+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.Customer;
+import com.avaje.tests.model.basic.Order;
+import com.avaje.tests.model.basic.ResetBasicData;
+
+public class TestQueryExists extends BaseTestCase {
+	@Test
+	public void testExists() {
+		ResetBasicData.reset();
+
+		Query<Order> subQuery=Ebean.find(Order.class).alias("sq").select("id").where().raw("sq.kcustomer_id = qt.id")
+				.query();
+		Query<Customer> query=Ebean.find(Customer.class).alias("qt").where().exists(subQuery).query();
+
+		query.findList();
+		String sql=query.getGeneratedSql();
+
+		Assert.assertTrue(sql.indexOf("exists (")>0);
+	}
+
+	@Test
+	public void testNotExists() {
+		ResetBasicData.reset();
+
+		Query<Order> subQuery=Ebean.find(Order.class).alias("sq").select("id").where().raw("sq.kcustomer_id = qt.id")
+				.query();
+		Query<Customer> query=Ebean.find(Customer.class).alias("qt").where().notExists(subQuery).query();
+
+		query.findList();
+		String sql=query.getGeneratedSql();
+
+		Assert.assertTrue(sql.indexOf("not exists (")>0);
+	}
+}