EF6学习笔记十一：调用、自动生成存储过程

要专业系统地学习EF前往《你必须掌握的Entity Framework 6.x与Core 2.0》这本书的作者（汪鹏，Jeffcky）的博客：https://www.cnblogs.com/CreateMyself/

前面说到EF中的原始查询，就是写SQL语句执行

那么还有存储过程的调用也是通过那几个方法来的

调用查询数据的存储过程使用：ctx.Database.SqlQuery<T>()  或者 ctx.DbSet<T>.SqlQuery()

调用Insert、Update、Delete操作的存储过程使用：ExceuteSqlCommand()或者ExceuteSqlCommandAsync()

调用存储过程

我们先手动地添加一个存储过程：select * from tb_products

create procedure GetProducts
as
begin
set nocount on;
select * from tb_Products;
set nocount off;
end
go

紧接着调用它，可以

var res = ctx.Database.SqlQuery<Product>("dbo.GetProducts");
Console.WriteLine(JsonConvert.SerializeObject(res,set));

然后再创建一个存储过程：select id,name from tb_products

create procedure GetProducts2
as
begin
select id,[name] from tb_Products
end
go

接收类型的属性数量和返回数据集的字段数量不一致，报错。得自己另外定义类型去接收

var res = ctx.Database.SqlQuery<Product>("dbo.getproducts2");
Console.WriteLine(JsonConvert.SerializeObject(res));
//  未经处理的异常:  System.Data.Entity.Core.EntityCommandExecutionException: The data reader is incompatible with the specified 'CodeFirstNamespace.Product'. A member of the type, 'Price', does not have a corresponding column in the data reader with the same name.

 来看看带参数的存储过程，在方法中该怎么写

-- 传递参数，name
create procedure GetProductsByName
(
@name as nvarchar(50)
)
as
begin
select *from tb_Products where [Name] =@name;
end
go

--  执行
exec GetProductsByName '砖头'
go

// 一个参数name
var parameter = new SqlParameter("@name","水泥");
var res = ctx.Database.SqlQuery<Product>("dbo.getproductsByName @name",parameter);
Console.WriteLine(JsonConvert.SerializeObject(res));
//  [{"Order":null,"Name":"水泥","Price":50.00,"Unit":"袋","FK_Order_Id":"469b82be-8139-4e67-b566-5b2b5f6d838d","Id":"d951e96d-a581-4f87-a567-bedb4c24eca3","AddTime":"2019-01-15T10:28:00.653"}]

 来看看多个参数的存储过程

--  两个参数，id,price
create procedure GetProducts3
(
@id as nvarchar(36), 
@price as decimal(18,2)
)
as
begin 
select * from tb_Products where id =@id and Price = @price
end
go

//  两个参数
var parameterList = new List<SqlParameter>
     {
            new SqlParameter(){ ParameterName="@id",SqlDbType = System.Data.SqlDbType.NVarChar,Value ="6495f22b-f1ef-4bd2-b81e-c49eaf6e2f21"},
            new SqlParameter(){ ParameterName="@price",SqlDbType=System.Data.SqlDbType.Decimal,Value=5}
       };
var parameterArr = parameterList.ToArray();
var res = ctx.Database.SqlQuery<Product>("dbo.getproducts3 @id,@price",parameterArr);
Console.WriteLine(JsonConvert.SerializeObject(res));
//[{"Order":null,"Name":"苹果","Price":5.00,"Unit":"斤","FK_Order_Id":"e18757db-1db8-4f7f-b702-79138709b304","Id":"6495f22b-f1ef-4bd2-b81e-c49eaf6e2f21","AddTime":"2019-01-15T10:35:03.36"}]
// 简直没有问题

 上面的都是执行的查询操作，来看看添加操作的存储过程，我们使用ExcuteSqlCommand()方法

--  添加数据
create procedure AddProduct
(
@name as nvarchar(50),
@price as decimal(18,2),
@unit as nvarchar(10)
)
as
begin
insert into tb_Products values(newid(),@name,@price,'469b82be-8139-4e67-b566-5b2b5f6d838d',getdate(),@unit)
end
go

var parameterList = new List<SqlParameter>
{
    new SqlParameter(){ ParameterName="@name",SqlDbType = System.Data.SqlDbType.NVarChar,Value ="花生"},
    new SqlParameter(){ ParameterName="@price",SqlDbType = System.Data.SqlDbType.Decimal,Value = 4.4},
    new SqlParameter(){ ParameterName ="@unit",SqlDbType = System.Data.SqlDbType.NVarChar,Value="斤"}
};
var paraArr = parameterList.ToArray();
var res = ctx.Database.ExecuteSqlCommand("dbo.addproduct @name,@price,@unit", paraArr);
Console.WriteLine(res);  //  result : 1

EF自动生成存储过程 

 上面的存储过程都是手动添加，现在我们在OnModelCreating方法中写配置，让它自动添加存储过程

modelBuilder.Entity<Order>().MapToStoredProcedures();

这样他会给你生成三个存储过程

public partial class jinshantest4 : DbMigration
    {
        public override void Up()
        {
            CreateStoredProcedure(
                "dbo.Order_Insert",
                p => new
                    {
                        Id = p.String(maxLength: 128),
                        OrderNO = p.String(),
                        Description = p.String(),
                        AddTime = p.DateTime(),
                    },
                body:
                    @"INSERT [dbo].[tb_Orders]([Id], [OrderNO], [Description], [AddTime])
                      VALUES (@Id, @OrderNO, @Description, @AddTime)"
            );
            
            CreateStoredProcedure(
                "dbo.Order_Update",
                p => new
                    {
                        Id = p.String(maxLength: 128),
                        OrderNO = p.String(),
                        Description = p.String(),
                        AddTime = p.DateTime(),
                    },
                body:
                    @"UPDATE [dbo].[tb_Orders]
                      SET [OrderNO] = @OrderNO, [Description] = @Description, [AddTime] = @AddTime
                      WHERE ([Id] = @Id)"
            );
            
            CreateStoredProcedure(
                "dbo.Order_Delete",
                p => new
                    {
                        Id = p.String(maxLength: 128),
                    },
                body:
                    @"DELETE [dbo].[tb_Orders]
                      WHERE ([Id] = @Id)"
            );
            
        }
        
        public override void Down()
        {
            DropStoredProcedure("dbo.Order_Delete");
            DropStoredProcedure("dbo.Order_Update");
            DropStoredProcedure("dbo.addOrder");
        }
    }

也可以对它进行详细配置，比如我指定insert存储过程的名称为“orderAdd” 

modelBuilder.Entity<Order>().MapToStoredProcedures(x => x.Insert(a => a.HasName("addOrder")));

跟新后，可以看到存储过程都添加 成功了

 

最后来调用一个EF为我们创建的存储过程

//  添加一个订单
var parameterList = new List<SqlParameter>
{
    new SqlParameter{ ParameterName="@Id",SqlDbType = System.Data.SqlDbType.NVarChar,Value = Guid.NewGuid().ToString()},
    new SqlParameter{ ParameterName="@OrderNO",SqlDbType = System.Data.SqlDbType.NVarChar,Value ="order435435"},
    new SqlParameter{ ParameterName="@Description",SqlDbType = System.Data.SqlDbType.NVarChar,Value="description4364537ryrtey"},
    new SqlParameter{ ParameterName="@AddTime",SqlDbType = System.Data.SqlDbType.DateTime,Value =DateTime.Now}
};
var paraArr = parameterList.ToArray();
var res = ctx.Database.ExecuteSqlCommand("dbo.addOrder @Id,@OrderNO,@Description,@AddTime",paraArr);
Console.WriteLine(res);  //  result:1

可以的