在JPA / Hibernate NamedQuery中指定数据库函数 [英] Specifying a database function in a JPA/Hibernate NamedQuery
问题描述
如何在JPA / Hibernate NamedQuery中指定数据库函数?
奇怪的是,休眠JQL不能识别RIGHT函数。在没有使用子字符串的情况下,hibernate中有没有一种方法可以在NamedQuery中指定任何有效的数据库函数?我不希望将其设置为原生查询或CriteriaQuery。
解决方案 JPQL JPA 2.1之前不支持直接使用数据库函数(由于使用JPQL功能而被调用的那些人)。根据JPA 2.1规范函数的调用方式如下:
lockquote
function_invocation ::
= FUNCTION(function_name {,function_arg} *)
function_arg :: =
文字|
state_valued_path_expression |
input_parameter |
scalar_expression
如果使用RIGHT函数,它就像:
$ b $
FUNCTION(RIGHT,some_string_possibly_path,3)
在Hibernate中,一种可能性是扩展方言,如这个答案。
How do I specify a database function in a JPA/Hibernate NamedQuery?
Oddly, hibernate JQL does not recognize the RIGHT function. Without using substring is there a way in hibernate to specify any valid database function in a NamedQuery? I'd prefer not to make it native query or CriteriaQuery.
JPQL prior JPA 2.1 do not support direct usage of database functions (others than those that get called as consequence of JPQL function in use).
According JPA 2.1 specification functions are invoked as follows:
function_invocation::= FUNCTION(function_name {, function_arg}*)
function_arg ::=
literal |
state_valued_path_expression |
input_parameter |
scalar_expression
In case of RIGHT function it goes like:
FUNCTION("RIGHT, "some_string_possibly_path", 3)
With Hibernate one possibility is to extend dialect as described in this answer.
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