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

Question

我想在规范的帮助下进行以下查询

从表中选择*，其中(order_quantity > 0 或product_verified = false)且 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 hibernate。您可以启用日志记录(对于 hibernate，它是“org.hibernate.sql”来调试)。这样您就可以看到生成的查询，这可能会帮助您自己调试这些查询。

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));

您基本上查询以下内容(仅 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));