插入和更新函数工作在单击按钮在C＃

Question

我试图插入和更新数据使用相同的按钮。我创建了方法（uniqueEmail（））来检查表中是否存在电子邮件地址。如果电子邮件没有预设，使用这种方法我试图插入数据。 这里是我的代码，请纠正我在哪里出错。

public partial class _Default : System.Web.UI.Page 
{ 
    SqlConnection con = new SqlConnection("Data Source=ADMIN-PC\\SQLEXPRESS;Initial Catalog=register;Integrated Security=True"); 

    protected void Page_Load(object sender, EventArgs e) 
    { 

    } 

    public void Button1_Click(object sender, EventArgs e) 
    { 
     con.Open(); 
     SqlCommand cmd = con.CreateCommand(); 
     cmd.CommandType = CommandType.Text; 
     if (uniqueEmail()==true) 
     { 
      cmd.CommandText = "update registeruser set email='" + TextBox1.Text + "', password='" + TextBox2.Text + "' where email='" + TextBox1.Text + "'"; 
     } 
     else 
     { 
      cmd.CommandText = "insert into registeruser values('" + TextBox1.Text + "', '" + TextBox2.Text + "')"; 
     } 

     cmd.ExecuteNonQuery(); 
     con.Close(); 

    } 
    public bool uniqueEmail() 
    { 
     string stremail; 
     string querye = "select count(email) as email from registeruser"; 
     SqlCommand cmd = new SqlCommand(querye, con); 
     SqlDataReader dr; 
     dr = cmd.ExecuteReader(); 
     while (dr.Read()) 
     { 
      try 
      { 
       stremail = dr["email"].ToString(); 
       return(stremail != "0"); 
       if (stremail != "0") 
       { 
        //errlblemail.Text = "email already exist"; 
        return false; 
       } 

      } 
      catch (Exception e) 
      { 
       string message = "error"; 
       message += e.Message; 
      } 
      finally 
      { 
       dr.Close(); 
      } 
     } 

     return true; 


    } 
} 

Answer 1

您需要检查特定的EMAILID的数量，而不是总数量。

修改为下面的代码：

public static bool uniqueEmail(string email) 
{ 
     string stremail; 
     string querye = "select count(email) as email from register where 
     email = '" + email + "'"; 
     //Remaining Code 
} 

public static void Button1_Click(object sender, EventArgs e) 
{ 
     con.Open(); 
     SqlCommand cmd = con.CreateCommand(); 
     cmd.CommandType = CommandType.Text; 
     if (uniqueEmail(TextBox1.Text)) == true) 
     //Remaining Code 
    } 

Answer 2

@nirmala就应该更换方法

public void EmailCheck() 
{ 
    string constring = ConfigurationManager.ConnectionStrings["ConnData"].ConnectionString; 
    SqlConnection con = new SqlConnection(constring); 
    SqlCommand cmd = new SqlCommand("Select * from EmailSignUp where EmailId= @EmailId", con); 
    cmd.Parameters.AddWithValue("@EmailId", this.txtEmail.Text); 
    con.Open(); 
    SqlDataReader dr = cmd.ExecuteReader(); 
    while (dr.Read()) 
    { 
     if (dr.HasRows == true) 
     { 
      MessageBox.Show("EmailId = " + dr[5].ToString() + " Already exist"); 
      txtEmail.Clear(); 
      break; 
     } 
    } 

} 

Answer 3

两件事情需要做

1. 传递电子邮件ID同时呼吁

   如果（uniqueEmail（）==真）

要

if (uniqueEmail(TextBox1.Text)==true) 

而在uniqueEmail方法chenage查询（）包括其中如下条件

public bool uniqueEmail(email) 
{ 
string stremail; 
string querye = "select count(email) as email from registeruser where email='" + email + "'"; 

//your remaining code 
} 

Answer 4

您好修女代码是只有正确的你需要把where子句找到已经存在于数据库中的电子邮件ID。

public partial class _Default : System.Web.UI.Page 
{ 
    SqlConnection con = new SqlConnection("Data Source=ADMIN-PC\\SQLEXPRESS;Initial Catalog=register;Integrated Security=True"); 

    protected void Page_Load(object sender, EventArgs e) 
    { 

    } 

    public void Button1_Click(object sender, EventArgs e) 
    { 
     con.Open(); 
     SqlCommand cmd = con.CreateCommand(); 
     cmd.CommandType = CommandType.Text; 
     if (uniqueEmail()==true) 
     { 
      cmd.CommandText = "update registeruser set email='" + TextBox1.Text + "', password='" + TextBox2.Text + "' where email='" + TextBox1.Text + "'"; 
     } 
     else 
     { 
      cmd.CommandText = "insert into registeruser values('" + TextBox1.Text + "', '" + TextBox2.Text + "')"; 
     } 

     cmd.ExecuteNonQuery(); 
     con.Close(); 

    } 
    public bool uniqueEmail() 
    { 
     string stremail; 
     string querye = "select count(email) as email from registeruser where email = '" +TextBox1.Text+ "'"; 
     SqlCommand cmd = new SqlCommand(querye, con); 
     SqlDataReader dr; 
     dr = cmd.ExecuteReader(); 
     while (dr.Read()) 
     { 
      try 
      { 
       stremail = dr["email"].ToString(); 
       return(stremail != "0"); 
       if (stremail != "0") 
       { 
        //errlblemail.Text = "email already exist"; 
        return false; 
       } 

      } 
      catch (Exception e) 
      { 
       string message = "error"; 
       message += e.Message; 
      } 
      finally 
      { 
       dr.Close(); 
      } 
     } 

     return true; 


    } 
}