我正在开发 Xamarin 多平台 native 移动应用。我正在使用 sqlite.net 数据库插件。
我创建了三个表:
public class OrderT
{
SQLiteConnection database;
[PrimaryKey, AutoIncrement]
public int id { get; set; }
public int client_id { get; set; }
public DateTime order_date { get; set; }
}
public class OrderDetailT
{
SQLiteConnection database;
[PrimaryKey, AutoIncrement]
public int id { get; set; }
public int order_id { get; set; }
public int quantity { get; set; }
public float price { get; set; }
}
public class ClientT
{
SQLiteConnection database;
[PrimaryKey, AutoIncrement]
public int id { get; set; }
public string client_name { get; set; }
}
如何在 Xamarin Sqlite 中运行这样的查询？由于Xamarin Sqlite中没有关系和外键的概念。
SELECT OrderT.*, OrderDetailT.*, ClientT.*
FROM OrderT, OrderDetailT, ClientT
WHERE OrderT.client_id = ClientT.id AND OrderT.id = OrderDetailT.order_id
最佳答案
How can I run a query like this in Xamarin Sqlite? Since there is no concept of relationships and foreign key in Xamarin Sqlite
您可以使用LinQ来实现这一目标。
示例:
var list = from orderT in db.Table<OrderT>()
from clientT in db.Table<ClientT>()
from orderDetailT in db.Table<OrderDetailT>()
where orderT.client_id == clientT.id
where orderT.id == orderDetailT.order_id
select new { client_name=clientT.client_name, client_id = orderT.client_id, order_id = orderDetailT.order_id,price=orderDetailT.price, quality=orderDetailT.quantity };
关于android - Xamarin SQLite Net - 从多个表中获取数据，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/46241941/