Java Spring Data JPA - 规范加入
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时间：2020-08-11 21:03:07 来源:igfitidea点击:
Spring Data JPA - Specifications join
提问by ByeBye
I have specification:
我有规格：
final String text = "%text%";
final Specifications<PersonEntity> spec = Specifications.where(
(root, query, builder) -> builder.like(builder.lower(root.join(PersonEntity_.addresses, JoinType.LEFT).get(AddressEntity_.addressLine1)), text)
).or(
(root, query, builder) -> builder.like(builder.lower(root.join(PersonEntity_.addresses, JoinType.LEFT).get(AddressEntity_.addressLine2)), text)
).or(
(root, query, builder) -> builder.like(builder.lower(root.join(PersonEntity_.addresses, JoinType.LEFT).get(AddressEntity_.city)), text)
)
After using:
使用后：
personRepository.findAll(spec);
In logs, I see, that JPA create a query where it joins addresses three times instead of once.
在日志中，我看到 JPA 创建了一个查询，它在其中连接地址三次而不是一次。
How can I write a Specification where addresses will be joined only once?
如何编写地址仅加入一次的规范？
采纳答案by ByeBye
I changed it to:
我把它改成：
Specifications.where(
(root, query, builder) -> {
final Join<PersonEntity, AddressEntity> addresses = root.join(PersonEntity_.address, JoinType.LEFT);
return builder.or(
builder.like(builder.lower(addresses.get(AddressEntity_.addressLine1)), text),
builder.like(builder.lower(addresses.get(AddressEntity_.addressLine2)), text),
builder.like(builder.lower(addresses.get(AddressEntity_.code)), text),
);
}
);
Now, it is joining only once.
现在，它只加入一次。
