Spring Data JPA - 规范加入

Question

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)
)

使用后：

personRepository.findAll(spec);

在日志中，我看到，JPA 创建了一个查询，它连接地址三次而不是一次。

如何编写一个地址将只连接一次的规范？

Answer 1

我改成：

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),
        );
    }
);

现在，它只加入一次。