如何在实体框架执行原始的SQL查询？ [英] How to execute raw sql query with in entity framework?

问题描述

我使用asp.net MVC 3与实体框架5.我有我的.edmx文件和放大器;能够与使用LINQ或SP我的数据库交互，但我想运行一些原始的SQL语句。我想是这样的：

I'm using asp.net mvc 3 with entity framework 5. I have my .edmx file & able to interact with my database using linq or SP, but I want to run some raw sql statement. I'm trying something like this:

Using(var ctx=new HREntities())
{
  ctx.Database.ExecuteSqlCommand("insert into Employees values {0}, {1}",   model.EMPLOYEEID, model.EMPLOYEENAME);
  ctx.SaveChanges();
}

，才有可能执行sql查询这种方式？谢谢你。

is it possible to execute sql query this way? Thanks.

推荐答案

您可以执行以下类型的查询：

You can execute the following types of queries:

1. 对于实体类型的SQL查询返回特定类型的实体。

1. SQL query for entity types which returns particular types of entities.

using (var ctx = new SchoolDBEntities())
 {

     var studentList = ctx.Students.SqlQuery("Select * from Student").ToList<Student>();

}

对于非实体类型的SQL查询返回一个原始数据类型。

SQL query for non-entity types which returns a primitive data type.

using (var ctx = new  SchoolDBEntities())
{

var studentName = ctx.Students.SqlQuery("Select studentid, studentname 
    from Student where studentname='New Student1'").ToList();
}


 //Error
 using (var ctx = new SchoolDBEntities())
 {                
     //this will throw an exception
     var studentName = ctx.Students.SqlQuery("Select studentid as id, studentname as name 
        from Student where studentname='New Student1'").ToList();
 }

 //SQL query for non-entity types:
  using (var ctx = new SchoolDBEntities())
  {
       //Get student name of string type
      string studentName = ctx.Database.SqlQuery<string>("Select studentname 
    from Student where studentid=1").FirstOrDefault<string>();
  }

原始的SQL命令到数据库中。

Raw SQL commands to the database.

      using (var ctx = new SchoolDBEntities())
      {

           //Update command
           int noOfRowUpdated = ctx.Database.ExecuteSqlCommand("Update student 
        set studentname ='changed student by command' where studentid=1");
          //Insert command
         int noOfRowInserted = ctx.Database.ExecuteSqlCommand("insert into student(studentname) 
        values('New Student')");
         //Delete command
         int noOfRowDeleted = ctx.Database.ExecuteSqlCommand("delete from student 
        where studentid=1");

       }

您还可以参考<一个href=\"http://blogs.microsoft.co.il/gilf/2009/11/25/execute-t-sql-statements-in-entity-framework-4/\">this

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