如何在实体框架中发送常规内联SQL

发布于 2024-10-16 06:46:30 字数 173 浏览 1 评论 0原文

现在先别生气。这仅适用于非常具体的情况。因此，我们不要问为什么我想通过 EF 发送内联字符串 SQL，而是尝试停留在“如何”的主题上。

我是否需要使用常规的旧 ADO.NET 按照老式路线执行此操作，或者 EF 是否为我提供了一种执行直接 sql select/nonquery 的方法？

提前致谢。

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回忆躺在深渊里 2024-10-23 06:46:30

您是否研究过Entity SQL？

实体框架问答：

string city = "London";
using (Entities entities = new Entities()) 
{
  ObjectQuery<Customers> query = entities.CreateQuery<Customers>(
    "SELECT VALUE c FROM Customers AS c WHERE c.Address.City = @city",
    new ObjectParameter("city", city)
  );

  foreach (Customers c in query)
    Console.WriteLine(c.CompanyName);
}

由于 Entity SQL 目前缺乏任何
DML 构造，不可能
问题插入、更新或删除
使用 Entity SQL 和对象的命令
服务

Have you investigated Entity SQL?

Entity Framework Q&A:

string city = "London";
using (Entities entities = new Entities()) 
{
  ObjectQuery<Customers> query = entities.CreateQuery<Customers>(
    "SELECT VALUE c FROM Customers AS c WHERE c.Address.City = @city",
    new ObjectParameter("city", city)
  );

  foreach (Customers c in query)
    Console.WriteLine(c.CompanyName);
}

Since Entity SQL currently lacks any
DML constructs, it is not possible to
issue Insert, Update, or Delete
commands using Entity SQL and Object
Services

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听，心雨的声音 2024-10-23 06:46:30

作为 ObjectQuery 的替代方案，如果您需要更多选项来跨越多个数据库表，请使用 context.Database.SqlQuery 和 SqlParameter >。

例子：

var searchId = new Guid("16144A52-A092-4876-9C55-A0AD0109F08A");

var sqlparam = new SqlParameter("sid", searchId);

using (var context = new Entities())
{
    var sql = @"SELECT t1.Name, t2.ChildName
        FROM dbo.Table1 as t1 
        INNER JOIN dbo.Table1 as t2 
            ON t1.Id = t2.ParentId 
        WHERE t1.Id = @sid"

    var result = context.Database.SqlQuery<Combined>(sql, sqlparam);

    foreach(var r in result)
    {
         Console.WriteLine(r.Name + r.ChildName)
    }
}


public class Combined
{
    public string Name { get; set; }
    public string ChildName { get; set; }
}

As an alternative to ObjectQuery if you need more options to cross over multiple database tables, make use of context.Database.SqlQuery<> and SqlParameter.

Example:

var searchId = new Guid("16144A52-A092-4876-9C55-A0AD0109F08A");

var sqlparam = new SqlParameter("sid", searchId);

using (var context = new Entities())
{
    var sql = @"SELECT t1.Name, t2.ChildName
        FROM dbo.Table1 as t1 
        INNER JOIN dbo.Table1 as t2 
            ON t1.Id = t2.ParentId 
        WHERE t1.Id = @sid"

    var result = context.Database.SqlQuery<Combined>(sql, sqlparam);

    foreach(var r in result)
    {
         Console.WriteLine(r.Name + r.ChildName)
    }
}


public class Combined
{
    public string Name { get; set; }
    public string ChildName { get; set; }
}

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~没有更多了~