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我很难弄清楚如何对代码中没有相互引用的 2 个表执行查询,例如,我有

Customer -> Product* where customer and product have reference to each other

和库存 -> 产品*,其中产品没有参考库存

我想找到所有没有库存的客户。

到目前为止我已经这样做了

var subQueryInv= DetachedCriteria.For<Inventory>();
        subQueryInv
            .Add(Restrictions.IsNotNull("Product.Id"))
            .SetProjection(Projections.Property<Inventory>(inv=> inv.Product.Id));

        var subQueryProd = DetachedCriteria.For<Product>();
        subQueryTire
            .Add(Subqueries.PropertyNotIn("Id", subQueryInv))
            .SetProjection(Projections.Property<Tire>(prod=> prod.Customer.Id));

        var subQueryCust= DetachedCriteria.For<Customer>();
        subQueryCust
            .Add(Subqueries.PropertyIn("Id", subQueryProd))
            .SetProjection(Projections.Property<TireSet>(cust => cust.Id));

那行得通,bt查询效率很低,它为库存部分生成这样的SQL ...WHERE Product.Id NOT IN (SELECT Inventory.ProductId FROM Inventory WHERE Inventory.ProductId IS NOT NULL)

因此,对于每条产品记录,它都在查询整个 Inventory 表。如何让子查询具有对父 ID 的引用,如下所示:

    ...WHERE Product.Id NOT IN (SELECT Inventory.ProductId FROM Inventory WHERE Inventory.ProductId IS NOT NULL AND Inventory.ProductId = Product.Id)

?

4

1 回答 1

2

您可以使用别名来引用主要标准

var subQueryInv= DetachedCriteria.For<Inventory>();
    .Add(Restrictions.IsNotNull("Product.Id"))
    .Add(Restrictions.PropertyEq("Product", "product"))
    .SetProjection(Projections.Property<Inventory>(inv => inv.Product.Id));

var subQueryProd = DetachedCriteria.For<Product>("product");
于 2012-08-14T05:39:00.730 回答