UPDATE语句改变错误记录

Question

• 我有4列一个DataGridView：UserID, FirstName, LastName, Email

• 当我双击某一行，另一种形式与4个文本框里面那些行的值，每个文本框有弹起单元格值

• 当我单击提交按钮时，该行将更新为文本框的值。

• 我与....where UserID = @UserID一起工作。但是，如果列单元格 我正在更改IS UserId，错误的行或无行将被修改。

问题

我如何可以编辑任何列值的行，它改变了右排没有增量列？

代码

public partial class EditUser : Form 
{ 
    public DataGridViewRow dgvRow; 
    public EditUser() 
    { 
     InitializeComponent(); 
    } 

    private void EditUser_Load(object sender, EventArgs e) 
    { 
     lbl5.Text = dgvRow.Cells[0].Value.ToString(); 
     txtUserID.Text = dgvRow.Cells[0].Value.ToString(); 
     txtFName.Text = dgvRow.Cells[1].Value.ToString(); 
     txtLName.Text = dgvRow.Cells[2].Value.ToString(); 
     txtEmail.Text = dgvRow.Cells[3].Value.ToString(); 
     label1.Visible = false; 
     txtUserID.Visible = false; 
    } 

    private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e) 
    { 
     this.Visible = false; 
    } 

    private void button1_Click(object sender, EventArgs e) 
    { 
     SqlConnection sc = new SqlConnection(); 
     SqlCommand com = new SqlCommand(); 
     sc.ConnectionString = (""); 
     sc.Open(); 
     com.Connection = sc; 
     com.CommandText = ("update JoshUserTable SET UserID = @UserID, FirstName=@FirstName,LastName=@LastName,Email=@Email where UserID = @UserID"); 
     com.Parameters.AddWithValue("@UserID", txtUserID.Text); 
     com.Parameters.AddWithValue("@FirstName", txtFName.Text); 
     com.Parameters.AddWithValue("@LastName", txtLName.Text); 
     com.Parameters.AddWithValue("@Email", txtEmail.Text); 
     com.ExecuteNonQuery(); 
     sc.Close(); 
    } 

    private void linkLabel2_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e) 
    { 
     label1.Visible = true; 
     txtUserID.Visible = true; 
     SqlConnection sc = new SqlConnection(); 
     SqlCommand con = new SqlCommand(); 
     sc.ConnectionString = (""); 
     sc.Open(); 
     con.Connection = sc; 
     con.CommandText = ("update JoshUserTable SET UserID = @UserID, FirstName=@FirstName,LastName=@LastName,Email=@Email where FirstName = @FirstName"); 
     con.Parameters.AddWithValue("@UserID", txtUserID.Text); 
     con.Parameters.AddWithValue("@FirstName", txtFName.Text); 
     con.Parameters.AddWithValue("@LastName", txtLName.Text); 
     con.Parameters.AddWithValue("@Email", txtEmail.Text); 
     con.ExecuteNonQuery(); 
     sc.Close(); 
    } 
} 

Answer 1

我认为你是在一个更大的问题，在所有运行。如果某个记录被另一个用户同时更改，该怎么办？您将运行并发问题。这就是为什么自动生成的CommandBuilder代码总是检查旧值。

对于您当前的代码，我添加了对原始用户ID的检查。

private void button1_Click(object sender, EventArgs e) 
{ 
    SqlConnection sc = new SqlConnection(); 
    SqlCommand com = new SqlCommand(); 
    sc.ConnectionString = ("My Connection String"); 
    sc.Open(); 
    com.Connection = sc; 

    /// check for original value in whereClause 
    com.CommandText = ("update JoshUserTable SET UserID = @NEW_UserID, 
         FirstName=@FirstName,LastName=@LastName,Email=@Email 
         where UserID = @ORIGINAL_UserID"); 


    com.Parameters.AddWithValue("@NEW_UserID", txtUserID.Text); 
    com.Parameters.AddWithValue("@ORIGINAL_UserID", INSERT_ORIGINAL_USERID); 


    com.Parameters.AddWithValue("@FirstName", txtFName.Text); 
    com.Parameters.AddWithValue("@LastName", txtLName.Text); 
    com.Parameters.AddWithValue("@Email", txtEmail.Text); 
    com.ExecuteNonQuery(); 
    sc.Close(); 
} 

并发问题仍然未解决撑....