我正在努力将Oracle Sql查询转换为Linq,但不确定如何继续。这是Sql查询:
SELECT *
FROM CustomerShip,
(SELECT DISTINCT b.ShipSeq AS shipSeq
FROM Orders a,
CustomerShip b
WHERE a.OrderId IN (SELECT OrderId
FROM Orders
WHERE CustomerId = @CustomerId
AND OrderType <> 'A')
AND b.CustomerId = @CustomerId
AND b.ShipSeq = a.CustShip
AND OrderStatus <> 'C'
GROUP BY b.ShipSeq) i
WHERE CustomerId = @CustomerId
AND (Address NOT LIKE '%RETAIL%STORE%')
AND ShipSeq = i.ShipSeq(+)
ORDER BY ShipTo DESC, OrderDate DESC;
转换为linq时,我试图将其分解为三个单独的查询。
var query1 = from c in CustomerShip
where c.CustomerId == customerId
&& !c.Address.Contains("RETAIL")
&& !c.Address.Contains("STORE")
orderby c.ShipTo descending, c.OrderDate descending
select c;
var query2 = from o in Orders
where o.CustomerId == customerId
&& !o.OrderType.Equals("A")
select o.OrderId;
var query3 = (from o in Orders
from c in CustomerShip
where c.CustomerId == customerId
&& c.ShipSeq == o.CustShip
&& !o.OrderStatus.Equals("A")
select c.ShipSeq).Distinct();
现在我正在尝试将它们全部组合成一个查询,但不确定如何进行。这是我要走的方向:
var query = from c in CustomerShip
let subquery = from o in Orders
where o.CustomerId == customerId
&& !o.OrderType.Equals("A")
select o.OrderId
from or in model.Orders
where subquery.Contains(or.OrderId)
&& c.CustomerId == customerId
&& c.ShipSeq == or.CustShip
&& !or.OrderStatus.Equals("A")
group c by c.ShipSeq
into i
select c.ShipSeq
where c.CustomerId == customerId
&& !c.Address.Contains("RETAIL")
&& !c.Address.Contains("STORE")
orderby c.ShipTo descending, c.OrderDate descending
select c, i;
更新
我有一个查询类型可以工作,但它需要几乎两分钟的时间来执行(与Oracle查询的.02s相比)并且结果的顺序不正确。有人看到我错过的东西吗?
var innerQuery = from x in model.Orders
where x.CustomerId == customerId
&& !x.OrderType.Equals("A")
select x.OrderId;
var result = from c in model.CustomerShip
join subQuery in
(
(from o in model.Orders
from c in model.CustomerShip
where c.CustomerId == customerId
&& innerQuery.Contains(o.OrderId)
&& !o.FLAG_ORD_STATUS.Equals("C")
&& c.ShipSeq == o.CustShip
select c.ShipSeq).Distinct()
) on c.ShipSeq equals subQuery into temp
from x in temp.DefaultIfEmpty()
where c.CustomerId == customerId
&& !c.Address.Contains("RETAIL")
&& !c.Address.Contains("STORE")
orderby c.ShipTo descending, c.OrderDate descending
select c;
答案 0 :(得分:6)
请记住,您只是在此处构建查询。在您执行ToList()
或.FirstOrDefault()
或其他任何操作之前,不会执行任何操作。因此,您可以在其他查询中使用查询,并在执行时创建一个大的SQL语句。
var query2 = from o in Orders
where o.CustomerId == customerId
&& !o.OrderType.Equals("A")
select o.OrderId;
var query3 = (from o in Orders
join c in CustomerShip on o.CustShip equals c.ShipSeq
where c.CustomerId == customerId
&& !o.OrderStatus.Equals("A")
&& query2.Contains(o.OrderId)
select c.ShipSeq).Distinct();
var query1 = from c in CustomerShip
from i in query3
where c.CustomerId == customerId
&& !c.Address.Contains("RETAIL")
&& !c.Address.Contains("STORE")
&& c.ShipSeq == i.ShipSeq
orderby c.ShipTo descending, c.OrderDate descending
select c;
但是,我非常确定您可以将query2和query3简化为:
var query3 = (from o in Orders
join c in CustomerShip on o.CustShip equals c.ShipSeq
where c.CustomerId == customerId
&& !o.OrderStatus.Equals("A")
&& !o.OrderType.Equals("A")
select c.ShipSeq).Distinct();
答案 1 :(得分:1)
尝试这样的事情。我为了解决错误而为一些类建模。如果您按ShipSeq分组,则不需要区分。只需从组中取出第一项就可以得到相同的结果。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
namespace ConsoleApplication60
{
class Program
{
static void Main(string[] args)
{
int customerID = 1234;
List<Order> CustomTypeA = Order.orders
.Where(x => (x.CustomerId == customerID) && (x.OrderType == "A") && (x.OrderStatus == "C")).ToList();
var results = (from CustA in CustomTypeA
join CustShip in Ship.CustomerShip on CustA.CustomerId equals CustShip.CustomerId
select new { CustA = CustA, CustShip = CustShip})
.Where(x => (!RetailStore(x.CustShip.Address)) && (x.CustA.CustShip == x.CustShip.ShipSeq))
.OrderByDescending(x => x.CustShip.OrderDate)
.GroupBy(x => x.CustShip.ShipSeq)
.Select(x => x.FirstOrDefault())
.Select(x => new {
CustomerID = x.CustShip.CustomerId,
Address = x.CustShip.Address,
OrderDate = x.CustShip.OrderDate
}).ToList();
}
static Boolean RetailStore(string address)
{
string pattern = "RETAIL.*STORE";
return Regex.IsMatch(address, pattern);
}
}
public class Order
{
public static List<Order> orders = new List<Order>();
public int CustomerId { get; set; }
public string OrderType { get; set; }
public string CustShip { get; set; }
public string OrderStatus { get; set; }
}
public class Ship
{
public static List<Ship> CustomerShip = new List<Ship>();
public int CustomerId { get; set; }
public string ShipSeq { get; set; }
public string Address { get; set; }
public DateTime OrderDate { get; set; }
}
}
答案 2 :(得分:0)
query2和query3合并到内部查询
var Innerquery = (from o in Orders
join c in CustomerShip on o.CustShip equals c.ShipSeq
where c.CustomerId == customerId
&& !o.OrderStatus.Equals("A")
&& !o.OrderType.Equals("A")
select c.ShipSeq).Distinct();
var query1 = from c in CustomerShip
from i in query3
where c.CustomerId == customerId
&& innerquery.Contains(c.CustomerId)
&& !c.Address.Contains("RETAIL")
&& !c.Address.Contains("STORE")
&& c.ShipSeq == i.ShipSeq
orderby c.ShipTo descending, c.OrderDate descending
select c;
或者您可以尝试Linqer http://www.sqltolinq.com
答案 3 :(得分:0)
可能有很多原因导致您的查询在EF中变慢 - 我建议使用分析器。
可能的原因是EF创建了一个低效的查询(通常数据库应该创建自己的优化,但我在使用EF和Oracle时遇到过错误的经验),或者,根据加载的结果数量,将其映射到实际对象是非常昂贵的。
一般来说,虽然在.NET世界中似乎不是一个流行的观点,但我建议创建一个View,或者在有复杂查询时使用dbcontext.Database.SqlQuery<CustomerShip>(sql)
,特别是在使用Oracle时,至少从我的经验来看和它在一起(已经有一段时间了,所以我可能错了。)