How to execute raw sql query with in entity framew

2019-03-20 13:15发布

问题:

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();
}

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

回答1:

You can execute the following types of queries:

  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>();
    
    }
    
  2. 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>();
      }
    
  3. 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");
    
           }
    

You can also refer this



回答2:

This has worked!!

using (var ctx = new HR())
        {

            ctx.Database.ExecuteSqlCommand("insert into Employees values (9, 'Beverage')");

            ctx.SaveChanges();
        }