Question

这是我的＆＃39; SQL＆＃39;查询并且必须通过＆＃39; UserId＆＃39;作为＆＃39;其中＆＃39;的唯一标识符查询中的子句。

SELECT aspnet_Roles.RoleName, aspnet_Roles.Description
FROM aspnet_Roles INNER JOIN
     aspnet_UsersInRoles ON aspnet_Roles.RoleId =  aspnet_UsersInRoles.RoleId INNER JOIN
     aspnet_Users ON aspnet_UsersInRoles.UserId = aspnet_Users.UserId
WHERE (aspnet_Users.UserId = @param)

我要传递参数的C＃代码是：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlTypes;

public partial class Forms_RolesMgt_RoleList_Default : System.Web.UI.Page
{
  protected void Page_Load(object sender, EventArgs e)
  {

    if (!this.IsPostBack)
    {
        DSRolesTableAdapters.aspnet_RoleUsersTableAdapter userRoleAdapter = new DSRolesTableAdapters.aspnet_RoleUsersTableAdapter();
        DataTable dt = new DataTable();
        Guid user = Guid.NewGuid();
        user = Guid.Parse(Session["UserId"] as string);
        Response.Write(user);
        dt = userRoleAdapter.GetDataByUserId(user);//At this line i am passing the parameter and getting the error
        UserRolesGrdView.DataSource = dt;
        UserRolesGrdView.DataBind(); 
    }
  }
}

运行时出错：无法启用约束。一行或多行包含违反非null，唯一或外键约束的值。

按查询预览数据时.xsd文件出错：无法将参数值字符串转换为Guid

我哪里错了？

Answer 1

在您的情况下，您应该使用存储过程

CREATE PROCEDURE [dbo].[Name]  
(@param uniqueidentifier
)
AS 
BEGIN
    SELECT aspnet_Roles.RoleName, aspnet_Roles.Description
    FROM aspnet_Roles INNER JOIN
    aspnet_UsersInRoles ON aspnet_Roles.RoleId = aspnet_UsersInRoles.RoleId INNER JOIN
    aspnet_Users ON aspnet_UsersInRoles.UserId = aspnet_Users.UserId
    WHERE (aspnet_Users.UserId = @param)
END

并在GetDataByUserId（）方法中为sp添加参数：

command.Parameters.Add("@param",SqlDbType.UniqueIdentifier).Value=userId;

将唯一标识符作为参数传递给SQL查询函数

1 个答案: