ServiceStack.OrmLite - 如何从外键查找中包含字段? [英] ServiceStack.OrmLite - how to include field from foreign key lookup?

问题描述

我正在试用 ServiceStack MVC PowerPack，正在试用包含的 OrmLite ORM，正在尝试从外键引用的表中获取数据，但不知道如何操作.

例如，在使用 Northwind 数据库的 OrmLite 示例中，是否可以返回包含ShipperTypeName"的 Shipper 对象作为通过外键ShipperTypeID"查找的字符串?

来自 http://www.servicestack.net/docs/ormlite/ormlite-overview，如果可能，我想将 ShipperName 字段添加到 Shipper 类:

[别名(托运人")]公共类托运人:IHasId{[自动递增][别名(ShipperID")]公共 int Id { 获取；放;}[必需的][索引(唯一=真)][字符串长度(40)]公共字符串 CompanyName { 获取；放;}[字符串长度(24)]公共字符串电话{得到;放;}[参考文献(typeof(ShipperType))]公共 int ShipperTypeId { 获取；放;}}[别名("ShipperTypes")]公共类 ShipperType : IHasId{[自动递增][别名("ShipperTypeID")]公共 int Id { 获取；放;}[必需的][索引(唯一=真)][字符串长度(40)]公共字符串名称 { 获取；放;}}

解决方案

为此，您需要使用包含您想要的所有字段的原始 SQL 并创建一个与 SQL 匹配的新模型，因此对于此示例，您将执行类似的东西:

公共类 ShipperDetail{公共 int ShipperId { 获取；放;}公共字符串 CompanyName { 获取；放;}公共字符串电话{得到;放;}公共字符串 ShipperTypeName { 获取；放;}}var rows = dbCmd.Select(@"SELECT ShipperId, CompanyName, Phone, ST.Name as ShipperTypeNameFROM Shippers S INNER JOIN ShipperTypes STON S.ShipperTypeId = ST.ShipperTypeId");Console.WriteLine(rows.Dump());

将输出以下内容:

<预><代码>[{ShipperId: 2,公司名称:Planes R Us，电话:555-PLANES，托运人类型名称:飞机},{ShipperId: 3,公司名称:我们无所不能！，电话:555-独角兽，托运人类型名称:飞机},{ShipperId: 4,公司名称:Trains R Us，电话:666-TRAINS，托运人类型名称:火车}]

I'm trying out the ServiceStack MVC PowerPack, and am trying the included OrmLite ORM and am trying to get data from a table referenced by a foreign key without any idea how to do so.

In the OrmLite examples that use the Northwind database, for example, would it be possible to return a Shipper object that included the "ShipperTypeName" as a string looked up through the foreign key "ShipperTypeID"?

From http://www.servicestack.net/docs/ormlite/ormlite-overview, I'd like to add the ShipperName field to the Shipper class if possible:

[Alias("Shippers")]
public class Shipper : IHasId<int>
{
    [AutoIncrement]
    [Alias("ShipperID")]
    public int Id { get; set; }

    [Required]
    [Index(Unique = true)]
    [StringLength(40)]
    public string CompanyName { get; set; }

    [StringLength(24)]
    public string Phone { get; set; }

    [References(typeof(ShipperType))]
    public int ShipperTypeId { get; set; }
}

[Alias("ShipperTypes")]
public class ShipperType : IHasId<int>
{
    [AutoIncrement]
    [Alias("ShipperTypeID")]
    public int Id { get; set; }

    [Required]
    [Index(Unique = true)]
    [StringLength(40)]
    public string Name { get; set; }
}

解决方案

To do this you would need to use Raw SQL containing all the fields you want and create a new Model that matches the SQL, so for this example you would do something like:

public class ShipperDetail
{
    public int ShipperId { get; set; }
    public string CompanyName { get; set; }
    public string Phone { get; set; }
    public string ShipperTypeName { get; set; }
}

var rows = dbCmd.Select<ShipperDetail>(
    @"SELECT ShipperId, CompanyName, Phone, ST.Name as ShipperTypeName
        FROM Shippers S INNER JOIN ShipperTypes ST 
                 ON S.ShipperTypeId = ST.ShipperTypeId");

Console.WriteLine(rows.Dump());

Which would output the following:

[
    {
        ShipperId: 2,
        CompanyName: Planes R Us,
        Phone: 555-PLANES,
        ShipperTypeName: Planes
    },
    {
        ShipperId: 3,
        CompanyName: We do everything!,
        Phone: 555-UNICORNS,
        ShipperTypeName: Planes
    },
    {
        ShipperId: 4,
        CompanyName: Trains R Us,
        Phone: 666-TRAINS,
        ShipperTypeName: Trains
    }
]

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