Question

我正在尝试从我的数据库加载客户对象，其中客户的名称可以包含特定字符串以及在特定字段中具有特定值的任何关联地址。我已经做了很多研究等等。这是构建此类查询的正确方法吗？如果不是，那么“更正确”的方法或更有效的方法是什么？谢谢你的时间。

我拥有LINQPad，这个查询是用它制作的。


var customerName = "J";
var street = "Rd";
var city = "asdf";
var state = "TN";
var zip = "27613";

var query = (
    from c in customers
        .Include("locations")
        .Include("locations.address")
    where
        c.name.Contains(customerName) ||
        c.locations.Any(l => l.address.street1.Contains(street)) ||
        c.locations.Any(l => l.address.street2.Contains(street)) ||
        c.locations.Any(l => l.address.city.Contains(city)) ||
        c.locations.Any(l => l.address.state.Contains(state)) ||
        c.locations.Any(l => l.address.zip.Contains(zip))
    select new
    {
        c.id,
        c.name,
        c.locationId,
        c.location,
        Locations = 
            from l in c.locations 
            where 
                l.address.street1.Contains(street) || 
                l.address.street2.Contains(street) || 
                l.address.city.Contains(city) ||
                l.address.state.Contains(state) ||
                l.address.zip.Contains(zip)
            select new
            {
                l.id,
                l.address,
                l.description,
                l.locationType
            }
    }
);

query.Dump();

这确实给了我想要的结果，但我想确保我这样做是对数据库最有礼貌的最佳方式。

我确信这是使用实体框架进行搜索的一种非常典型的模式。

Answer 1

而不是两次写这个大谓词，我会翻转它。此外，当你进行投射时，Include是完全没必要的。

var query = 
    from l in c.locations
    where 
        l.customer.name.Contains(customerName) ||
        l.address.street1.Contains(street) || 
        l.address.street2.Contains(street) || 
        l.address.city.Contains(city) ||
        l.address.state.Contains(state) ||
        l.address.zip.Contains(zip)
    group l by l.customer into g
    select new
    {
        id = g.Key.id,
        name = g.Key.name,
        // etc.
        Locations = from l2 in g
                    select new
                    {
                        l2.id,
                        l2.address,
                        l2.description,
                        l2.locationType
                    }
    };

实体框架多个条件，寻找正确性或更好的方式

1 个答案: