使用Criteria API的动态JPA 2.0查询 [英] Dynamic JPA 2.0 query using Criteria API
问题描述
我有一个很常见的用例我猜:用户提供任意数量的搜索参数X要和/或连接:like:
从Foo中选择e,其中(name = X1或name = X2。 。或name = Xn)
方法或CriteriaBuilder不动态:
谓词或(谓语...限制)
想法?样本?
在你的情况下,我宁愿使用 (Collection)中的表达式#
,以避免循环并构建一个复合 动态定义
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery&Foo> cq = cb.createQuery(Foo.class);
元模型m = em.getMetamodel();
EntityType&Foo> Foo_ = m.entity(Foo.class);
根< Foo> foo = cq.from(Foo_);
cq.where(my.get(Foo_.name).in(params));
您可能需要检查使用Criteria API和Metamodel API的基本类型安全查询获取更多详细信息。
I am a bit stucked constructing a dynamic query using the CriteriaBuilder of JPA 2.0.
I have quite a common use case I guess: User supplies a arbitrary amount of search parameters X to be and / or concatenated: like :
select e from Foo where (name = X1 or name = X2 .. or name = Xn )
The Method or of CriteriaBuilder is not dynamic:
Predicate or(Predicate... restrictions)
Ideas? Samples?
In your case, I would rather use Expression#in(Collection)
to avoid having to loop and to build a compound Predicate
dynamically:
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Foo> cq = cb.createQuery(Foo.class);
Metamodel m = em.getMetamodel();
EntityType<Foo> Foo_ = m.entity(Foo.class);
Root<Foo> foo = cq.from(Foo_);
cq.where(my.get(Foo_.name).in(params));
You might want to check Basic Type-Safe Queries Using the Criteria API and Metamodel API for more details.
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