Add parser test case for #334.

sharding-jdbc-core/src/test/resources/parser/select.xml → sharding-jdbc-core/src/test/resources/parser/select_expression.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <asserts>
+    <!--<assert id="assertSelectFuncWithSingleTable">-->
+        <!--<tables>-->
+            <!--<table name="t_order" alias="o"/>-->
+        <!--</tables>-->
+        <!--<order-by-columns>-->
+            <!--<order-by-column name="DATE(o.atime)" order-by-type="DESC" />-->
+        <!--</order-by-columns>-->
+    <!--</assert>-->
     <assert id="assertSelectNotEqualsWithSingleTable" parameters="1">
         <tables>
             <table name="t_order_item" />

sharding-jdbc-core/src/test/resources/sql/select_expression.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <sqls>
+    <sql id="assertSelectFuncWithSingleTable" value="SELECT DATE(o.atime) FROM t_order AS o ORDER BY date(o.atime) DESC" type="H2,MySQL"/>
     <sql id="assertSelectNotEqualsWithSingleTable" value="SELECT * FROM t_order_item WHERE item_id &lt;&gt; %s ORDER BY item_id" />
     <sql id="assertSelectEqualsWithSingleTable" value="SELECT * FROM t_order WHERE user_id = %s AND order_id = %s" />
     <sql id="assertSelectBetweenWithSingleTable" value="SELECT * FROM t_order WHERE user_id BETWEEN %s AND %s AND order_id BETWEEN %s AND %s ORDER BY user_id, order_id" />