使用DbSet< TEntity> .SqlQuery（sqlcmd，params） [英] Using DbSet<TEntity>.SqlQuery(sqlcmd, params)

问题描述

有没有人有一个在CTP5中使用此功能的好例子？

据我所知，此功能允许将SqlQuery的结果具体化为被跟踪的对象实例由DbContext通过DbSet上的SqlQuery方法，而DbContext.Database.SqlQuery< TEntity>没有。

DbContext.Database.SqlQuery< TEntity>的一般示例是：

        static void Main（string [] args）

        {

           使用（MyContext db = new MyContext（））

            {

               串SQLCMD = QUOT; SELECT * FROM myTable的"

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP ;&NBSP;&NBSP;&NBSP;&NBSP; //查询对myTable的所有项目

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP ;&NBSP;&NBSP;&NBSP; IEnumerable的< myEntity所>的SQLQuery = db.Database.SqlQuery< myEntity所>（SQLCMD）;

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; &NBSP;的foreach（在的SQLQuery myEntity所项）

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; {

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; Console.WriteLine（" - {0} - {1} - {2}"，item.field0，item.field1，item.field2）;

     &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP; }


                Console.WriteLine（"按任意键继续。"）;
$
              &NBSP;&NBSP; Console.ReadKey（）;
$




           &NBSP; }

解决方案

Cborcher，

 

这里是一个使用DbSet<> .SqlQuery的示例。 
假设您已定义以下实体和上下文：

< span style ="font-family：Calibri; font-size：small"> 

   
public class
产品

   
{

       
public int Id {
获得; set ; }

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;
public string 名称{
获得; set ; }

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;
public decimal 价格{
获得; set ; }

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;
public int CategoryId {
获得; set ; }

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;
public 类别类别{
获得; set ; }

&NBSP;&NBSP;&NBSP;
}

 

&NBSP;&NBSP;&NBSP;
public class
类别

   
{

       
public int Id {
获得; set ; }

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;
public string 名称{
获得; set ; }

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;
public ICollection < 产品>产品{
获取; set ; }

&NBSP;&NBSP;&NBSP;
}

 

&NBSP;&NBSP;&NBSP;
public class
ProductsContext ：<跨度风格=" 颜色：＃2b91af ">
的DbContext

   
{

       
public DbSet < 产品>产品{
获取; set ; }

&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;
public DbSet < 分类>类别{
获取; set ; }

&NBSP;&NBSP;&NBSP;
}

 

默认情况下，Product实体将映射到数据库中名为Products的表。 
您可以使用SqlQuery查询和跟踪所有产品，如下所示：

 

   
使用（ var context =
新 ProductsContext （））

   
{

       
列表< 产品>产品= context.Products.SqlQuery（的" SELECT * FROM产品" ）。ToList（）;

   
}

 

希望这会有所帮助。

 

谢谢，

亚瑟

Does anyone have a good example of using this feature in CTP5?

As I understand this feature allows the results of the SqlQuery to be materialized into object instances that are tracked by the DbContext via the SqlQuery method on DbSet while the DbContext.Database.SqlQuery<TEntity> does not.

A generic example of the DbContext.Database.SqlQuery<TEntity> is :

        static void Main(string[] args)
        {
            using (MyContext db = new MyContext())
            {
                string sqlcmd = "SELECT * FROM myTable"

                // Query for all items in myTable

                IEnumerable<MyEntity> sqlQuery = db.Database.SqlQuery<MyEntity>(sqlcmd);
                foreach (MyEntity item in sqlQuery)
                {
                    Console.WriteLine(" - {0} - {1} - {2}", item.field0, item.field1, item.field2);
                }

                Console.WriteLine("Press any key to continue.");
                Console.ReadKey();


            }

解决方案

Cborcher,

 

Here’s an example of using DbSet<>.SqlQuery.  Let’s assume you have the following entities and context defined:

 

    public class Product

    {

        public int Id { get; set; }

        public string Name { get; set; }

        public decimal Price { get; set; }

        public int CategoryId { get; set; }

        public Category Category { get; set; }

    }

 

    public class Category

    {

        public int Id { get; set; }

        public string Name { get; set; }

        public ICollection<Product> Products { get; set; }

    }

 

    public class ProductsContext : DbContext

    {

        public DbSet<Product> Products { get; set; }

        public DbSet<Category> Categories { get; set; }

    }

 

By default the Product entity will be mapped to a table called Products in the database.  You can use SqlQuery to query for and track all products like so:

 

    using (var context = new ProductsContext())

    {

        List<Product> products = context.Products.SqlQuery("select * from products").ToList();

    }

 

Hope this helps.

 

Thanks,

Arthur

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