how to get autoincrement id in asp.net c#

Question

2.00/5 (2 votes)

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pls some one tell that how to get autoincreamented id in asp.net c#, i write the code but it throws error

Cannot implicitly convert type 'object' to 'int'. An explicit conversion exists (are you missing a cast?)

and code is

C#

public void gen1()
{
    con.Open();
    int a = 0;
    SqlCommand com = new SqlCommand("select max(id) from Category", con);
    a = com.ExecuteScalar();
    TextBox4.Text = Convert.ToString(a);
    con.Close();
}

pls help me to correct...

Posted 30-Oct-12 20:23pm

chander_rani

Updated 30-Oct-12 20:49pm

_Amy

v2

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4 solutions

Solution 1

Try This,

C#

public void Autogenrate()
{
    int r;
    try
    {
      con = new SqlConnection("data source=XYZ; user id=ABC; password=***; initial catalog=Detail");
   con.Open();
        SqlCommand cmd = new SqlCommand("Select max(id) from empp1", con);
        SqlDataReader dr = cmd.ExecuteReader();

        if (dr.Read())
        {

            string d = dr[0].ToString();
            if (d == "")
            {

                id.Text = "1001";//set the value in textbox which name is id

            }
            else
            {

                r = Convert.ToInt32(dr[0].ToString());
                r = r + 1;
                id.Text = r.ToString();
            }
        }
        con.Close();
        con.Open();

      cmd.CommandText = "insert empp1 values('" + id.Text + "','" +   txtName.Text + "','" + txtCity.Text + "')";

        cmd.ExecuteNonQuery();
    }

    catch (Exception ex)
    {
        Response.Write("<script>alert("+ex.Message+")</script>");
    }
    finally
    {
        con.Close();
    }
}

Posted 30-Oct-12 20:32pm

ijmar86

Updated 30-Oct-12 20:49pm

v2

Comments

Member 12896830 20-Dec-16 2:08am

what is this id.Text = "1001";
can you please explain

Solution 4

you can increment the id in table ,

click here

Posted 18-Nov-13 22:30pm

King Fisher

Solution 3

use this code for auto increment
http://sourcecodemaster.blogspot.in/2013/11/auto-increment-id-in-cnet.html[^]

Posted 18-Nov-13 19:27pm

mahesh005

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_Amy · Accepted Answer · 2012-10-30T20:55:00

Solution 2

Hi Rani,
Try replacing

C#

a = com.ExecuteScalar();

with

C#

a = Conver.ToInt32(com.ExecuteScalar());

Check SqlCommand.ExecuteScalar Method[^] which returns object. You need to cast that object to a specified type.

It'll work out.
--Amit

Posted 30-Oct-12 20:55pm

_Amy

v2

Comments

bbirajdar 31-Oct-12 3:00am

This should work .. +5

_Amy 31-Oct-12 3:01am

Thanks! :)