java如何使用规范在mysql查询中生成两个“或”条件和多个“和”条件

Question

我想在规范的帮助下进行以下查询

select * from table where (order_quantity > 0 or product_verified = false) and sku = "12345";

下面是我的代码，但我得到了一个错误的结果集

Specification<JitOrderItem> specification = JitOrderItemSpecification.findAll();

specification = Specifications.where(specification).and(
                    Specifications.where(specification).or(JitOrderItemSpecification.filterByJitOrderQuantityGreaterThan(0))
                    .or(Specifications.where(specification).and(JitOrderItemSpecification.filterByProductVerified(false)))

                );
specification = Specifications.where(specification).and(JitOrderItemSpecification.filterBySku(sku));

Answer 1

我假设你正在使用JPA，可能是hibernate。您可以启用日志记录（对于hibernate，调试时使用“org.hibernate.sql”）。这样您就可以看到生成的查询，这可能有助于您自己调试这些查询

查看您的代码，您的最终规范如下所示：

Specifications.where(
    Specifications.where(JitOrderItemSpecification.findAll())
        .and(
            Specifications.where(JitOrderItemSpecification.findAll())
                .or(JitOrderItemSpecification.filterByJitOrderQuantityGreaterThan(0))
                .or(Specifications.where(JitOrderItemSpecification.findAll()).and(JitOrderItemSpecification.filterByProductVerified(false)))
        )
)
.and(JitOrderItemSpecification.filterBySku(sku));

您基本上是在查询以下内容（仅限WHERE子句）：

(
    ALL JitOrderItems
    AND
    (
        ALL JitOrderItems
        OR 
        OrderQuantityGreaterThan 0
        OR 
        (
            ALL JitOrderItems
            AND
            ProductVerified false
        )
    )
)
AND
JitOrderItemSpec.filterBySku(sku)

你想要的可能是：

Specifications.where(
    JitOrderItemSpecification.filterByJitOrderQuantityGreaterThan(0).or(JitOrderItemSpecification.filterByProductVerified(false)))
    .and(JitOrderItemSpecification.filterBySku(sku));