JPQL
概述Java Presistence Query Language
基于首次在EJB2.0中引入的EJB查询语言(EJB QL),Java持久化查询语言(JPQL)是一种可移植的查询语言,旨在以面向对象表达式语言的表达式,将SQL语法和简单查询语义绑定在一起.使用这种语言编写的查询是可移植的,可以被编译成所有主流数据库服务器上的SQL.
选择查询SELECT <select_expression>
FROM <from_clause>
[WHERE <conditional_expression>]
[ORDER BY <order_by_clause>]
聚合查询SELECT <select_expression>
FROM <from_clause>
[WHERE <conditional_expression>]
[GROUP BY <group_by_clause>]
[HAVING <conditional_expression>]
[ORDER BY <order_by_clause>]
更新查询UPDATE <entity name>[ [AS ] <identification variable>]
SET <update_statement>{,<update_statement>}*
[WHERE <conditional_expression>]
删除查询DELETE FROM <entity name>[ [AS ] <identification variable>]
[WHERE <conditional_expression>]