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>]