DbParameterCollection 不包含 AddWithValue 的定义

Question

Getting above error on the last line of the following code. I'm using EF Core 1.1 . Trying to follow this suggestion.

using Microsoft.EntityFrameworkCore;
using System.Collections.Generic;
using System.Data;
using System.Data.Common;
using System.Data.SqlClient; //Visual Studio had greyed out this line suggesting this as unnecessary.

var conn = _context.Database.GetDbConnection();

var cmd = conn.CreateCommand();
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = "MySproc";
cmd.Parameters.AddWithValue("@MyParameter", 42);

Answer 1

Here's the equivalent code using just the System.Data.Common APIs. (It can be used with any ADO.NET provider.)

var parameter = cmd.CreateParameter();
parameter.ParameterName = "@MyParameter";
parameter.Value = 42;

cmd.Parameters.Add(parameter);

Answer 2

添加对 System.Data.SqlClient 的引用并将您的 DbConnection 实例转换为 SqlConnection。

Answer 3

In dotnet core 3+ running command is broken. To fix it, change System.Data.SqlClient to Microsoft.Data.SqlClient