使用標準

Question

休眠嵌套查詢是否有更多鈔票來創建一個標準生成以下SQL：

select name from (select distinct name from person) as aliasname order by lower(name); 

這裏有兩個SQL -

1. select distinct name from person

2. select name from <output of 1> as aliasname order by lower(name)

我想創建標準，然後做criteria.list()

Answer 1

我沒有答案給你，但你爲什麼要做第二次選擇？

SELECT DISTINCT NAME FROM PERSON AS ALIASNAME ORDER BY LOWER(NAME) 

會返回相同的數據。

Answer 2

我認爲，這將滿足您的需求：

criteria.addOrder(Order.asc("name").ignoreCase()) 
     .setProjection(Projections.distinct(Projections.property("name"))) 
     .list(); 

或者，這個標準使用的DetachedCriteria有名字的投影爲子查詢：

DetachedCriteria distinctNamesCriteria = DetachedCriteria.forClass(Person.class); 
distinctNamesCriteria.setProjection(Projections.distinct(Projections.property("name"))); 

criteria.add(SubQueries.propertyIn("name", distinctNamesCriteria)) 
     .addOrder(Order.asc("name").ignoreCase()) 
     .list();