java - 如何使用规范在mysql查询中使用多个“AND”条件创建两个“OR”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";

以下是我的代码，但我得到了错误的结果集

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

我假设您正在使用 JPA，可能是休眠的。您可以启用日志记录（对于休眠，它是“org.hibernate.sql”来调试）。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。

查看您的代码，您的最终规范将如下所示：

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)

您想要的可能是以下内容：

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