why dr.hasrows shows false even data present in DB?

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hI,

can anyone know why dr.hasrows shows false even data present in DB??

C#

 protected void btnchange_Click(object sender, EventArgs e)
    {
        int changed;
        string loginemailid = txtloginemailid.Text.Trim();
        string oldpass = txtoldpassword.Text.Trim();
        string newpass = txtnewpassword.Text.Trim();
        
            SqlConnection cn = new SqlConnection(ConfigurationManager.AppSettings["constring"].ToString());
            //SqlConnection cn = new SqlConnection(ConfigurationManager.ConnectionStrings["Connection"].ConnectionString);
            cn.Open();
            SqlCommand cmd = new SqlCommand("update tbl_register set password='" + newpass  + "',conpassword='" + newpass + "' where loginemailid='" + loginemailid  + "' and password='"+ oldpass +"'", cn);
            SqlDataReader dr=cmd.ExecuteReader();
            if (dr.HasRows)
            {
                if (dr.Read())
                {
                    loginemailid = dr["loginemailid"].ToString();
                    oldpass = dr["password"].ToString();
                    newpass = dr["password"].ToString();
                }
                dr.Close();
    }
           
            else
            {
                lblmsg.Text = "Updation Failed,Ensure Your Login Information Is Correct";
            }
    }
}

Posted 12-Feb-12 22:52pm

sathiyak

Updated 12-Feb-12 22:55pm

Syed Salman Raza Zaidi

v2

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4 solutions

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Syed Salman Raza Zaidi · Answer 1 · 2012-02-12T22:56:00

Solution 1

Because you are making an update command not selecting(ie reading) records,You should first select the records then update password if reader reads the records

Posted 12-Feb-12 22:56pm

Syed Salman Raza Zaidi

Updated 12-Feb-12 22:57pm

v2

Comments

Herman<T>.Instance 13-Feb-12 5:06am

that is indeed the reason!

uspatel · Answer 2 · 2012-02-12T22:58:00

Solution 3

You are using upadate command.
SqlDataReader work only with select command.
here you should use

C#

cmd.ExecuteNonQuery();

C#

SqlCommand cmd = new SqlCommand("update tbl_register set password='" + newpass  + "',conpassword='" + newpass + "' where loginemailid='" + loginemailid  + "' and password='"+ oldpass +"'", cn);

          cmd.ExecuteNonQuery();
lblmsg.Text = "Record Updated";

Posted 12-Feb-12 22:58pm

uspatel

Updated 12-Feb-12 23:25pm

v3

Comments

RDBurmon 13-Feb-12 5:32am

my +5

uspatel 13-Feb-12 5:33am

Thanks Rahul.......

Bernhard Hiller · Answer 3 · 2012-02-12T22:56:00

Solution 2

You do an update query - that does not return any rows. You need a select query to get the values.
Since you want to update and check, do:

C#

int n=cmd.ExecuteNonQuery();
if (n==1)
{
    //OK
}
else
{
    //failure
}

Posted 12-Feb-12 22:56pm

Bernhard Hiller

Updated 12-Feb-12 22:58pm

v2

Guo KeXin · Answer 4 · 2012-02-12T23:03:00

Solution 4

SqlDataReader used in select command,if you use SqlDataReader in update command,the returned SqlDaraReader has No Data,so the returned SqlDataReader.HasRows is false.

Posted 12-Feb-12 23:03pm

Guo KeXin

Comments

RDBurmon 13-Feb-12 5:31am

my +5