如何从C＃代码更新和删除数据到SQL Server（我做了INSERT方法） [英] How to Update and Delete data into SQL Server from C# code (i have made INSERT METHOD)

问题描述

public bool Insert(User user)
        {
            SqlConnection con = new SqlConnection(new Connection().GetConnectionString());

            string sql = "INSERT INTO User (Email) values (@Email)";
            con.Open();
            SqlCommand cmd = new SqlCommand(sql, con);
            cmd.Parameters.Add("@Email", SqlDbType.VarChar);
            cmd.Parameters["@Email"].Value = User.email;
            //cmd.ExecuteNonQuery();

            bool isInserted = cmd.ExecuteNonQuery() > 0;
            return isInserted;

        }

推荐答案

如何：

1. SQL Update [ ^ ]

2. SQL删除 [ ^ ]

但是，修改它们以使用参数化查询以防止 sql注入 [ ^ ]。例如：

更新参数：

How to:
1. SQL Update[^]
2. SQL Delete[^]
However, modify them to use parameterized query so as to prevent sql injection[^]. For example:
Update Parameter:

string sql = "UPDATE users set email = @email where userid= @userid"
SqlCommand cmd = new SqlCommand(sql, con);
cmd.Parameters.AddWithValue("@userid",txtUserID);
cmd.Parameters.AddWithValue("@email",txtEmail);
cmd.ExecuteNonQuery();

删除参数：

Delete Parameter:

string sql = "DELETE FROM users where userid= @userid"
SqlCommand cmd = new SqlCommand(sql, con);
cmd.Parameters.AddWithValue("@userid",txtUserID);
cmd.ExecuteNonQuery();

Ref：简单插入选择更新和删除ASP.Net使用MYSQL数据库

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