如何在JPQL中应用正则表达式? [英] How to apply regular expression in JPQL?

问题描述

我正在使用JPA(休眠)作为持久层.

I'm using JPA (Hibernate) as the persistence layer.

我需要基于正则表达式添加WHERE子句， 这样的一些模式是SELECT * FROM TableName where REGEXP_LIKE(ColumnName，'Pattern').从结果中得到的是字符串列表，但是我需要从数据库中获取映射的实体作为对象而不是字符串.

I need to add a WHERE clause based on a regular expression, such some pattern are SELECT * FROM TableName where REGEXP_LIKE(ColumnName, 'Pattern'). What I get from the result is the list of string but I need to get mapped entities from the DB as an object not a string.

据我所知，JPQL可以将结果作为对象返回，但是JPQL似乎不支持正则表达式，因为它是Oracle的专有扩展.

From my knowledge JPQL can return the result as an object but JPQL doesn't seem to support regular expressions, as it's a propietary extension from Oracle.

如何将正则表达式应用于JPQL?我还需要了解什么?

How can I apply regular expression to the JPQL?, what else should I need to know?

推荐答案

JPQL中没有完整的正则表达式，但是有模式值.根据规范 JPQL 2.2(p.188):

There are no full regular expressions in JPQL but there are pattern values. According to the specification JPQL 2.2 (p. 188):

pattern_value是字符串文字或字符串值输入参数，其中下划线(_)代表任何单个字符，百分号(％)字符代表任何字符序列(包括空序列)，而所有其他角色代表自己.

The pattern_value is a string literal or a string-valued input parameter in which an underscore (_) stands for any single character, a percent (%) character stands for any sequence of characters (including the empty sequence), and all other characters stand for themselves.

[...]

示例:

• address.phone像"12％3"一样，对于"123"，"12993"为true，对于"1234"为false

• address.phone LIKE ‘12%3’ is true for ‘123’ ‘12993’ and false for ‘1234’

asentence.word像"l_se"一样对"lose"是正确的，而对于"loose"则为false

asentence.word LIKE ‘l_se’ is true for ‘lose’ and false for ‘loose’

aword.加下划线的类似"_％" ESCAPE"\"，对于"_foo"为true，对于"bar"为false

aword.underscored LIKE ‘_%’ ESCAPE ‘\’ is true for ‘_foo’ and false for ‘bar’

address.phone与"123％3"类似，对于"123"和"12993"为假，对于"1234"为true

address.phone NOT LIKE ‘12%3’ is false for ‘123’ and ‘12993’ and true for ‘1234’

如果要使用更高级的正则表达式构造，则需要使用本机查询.

If you want more advanced regular expression constructs you need to use native queries.

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