cannot implicitly convert type 'string' to 'int' in c#

Jyoti Jodha

9y9kWindows Forms

cannot implicitly convert type 'string' to 'int' in c# Windows Application

private int billno(string p)

{

string Billno = "0";

cmd = new SqlCommand(p, con);

con.Open();

SqlDataReader reader = cmd.ExecuteReader();

if (reader.Read())

{

Billno = reader[0].ToString();

}

reader.Close();

return Billno;

con.Close();

}

private void btn_Insert_Click(object sender, EventArgs e)

{

int Billno = billno("Select ISNULL(Max(Billno+1),1) From MainBillForm");

}

12 Replies

Know the answer? Post it — somebody with the same question will find it here.

Karthi Keyan9y ago
Accepted answer
private string billno(string p)
{
string Billno = "0";
cmd = new SqlCommand(p, con);
con.Open();
SqlDataReader reader = cmd.ExecuteReader();
if (reader.Read())
{
Billno = reader[0].ToString();
}
reader.Close();
return Billno;
con.Close();
}

change int into string.
Bidyasagar Mishra9y ago
Change
private int billno(string p)
{
}
to
private string billno(string p)
{
}
it will give you a string type return
Jyoti Jodha9y ago
hello sir

last 3 records i am save direct database
and other records are save in windows form
so now i am want to my all records save like last 3 records....
Jyoti Jodha9y ago
Thanx
@
Nitin Sontakke

@
Gnanavel Sekar
@
Karthi Keyan
Gnanavel Sekar9y ago
Use finally to overcome this error

foreach (DataGridViewRow g1 in dataGridView.Rows)
{
try
{
con.Open();
SqlCommand cmd = new SqlCommand("insert into MainBillForm Values ('" + Billno + "','" + Nametxt.Text + "','" + Phtxt.Text + "','" + Datetxt.Text + "','" + ONtxt.Text + "','" + g1.Cells[0].FormattedValue.ToString() + "','" + g1.Cells[1].FormattedValue.ToString() + "','" + g1.Cells[2].FormattedValue.ToString() + "','" + g1.Cells[3].FormattedValue.ToString() + "','" + g1.Cells[4].FormattedValue.ToString() + "','" + g1.Cells[5].FormattedValue.ToString() + "','" + g1.Cells[6].FormattedValue.ToString() + "','" + TotalTaxtxt.Text + "','" + totalamounttxt.Text + "')", con);
cmd.ExecuteNonQuery();
MessageBox.Show("Records Inserted SuccessFully");
}
catch (Exception ex)
{
throw ex; //TODO: Please log it or remove the catch
}
finally
{
con.close();
}
}
Nitin Sontakke9y ago
Also, write separate classes for database access.
Jyoti Jodha9y ago
Error Show in this Code
"the connection was not closed the current state is open"

foreach (DataGridViewRow g1 in dataGridView.Rows)
{

SqlCommand cmd = new SqlCommand("insert into MainBillForm Values ('" + Billno + "','" + Nametxt.Text + "','" + Phtxt.Text + "','" + Datetxt.Text + "','" + ONtxt.Text + "','" + g1.Cells[0].FormattedValue.ToString() + "','" + g1.Cells[1].FormattedValue.ToString() + "','" + g1.Cells[2].FormattedValue.ToString() + "','" + g1.Cells[3].FormattedValue.ToString() + "','" + g1.Cells[4].FormattedValue.ToString() + "','" + g1.Cells[5].FormattedValue.ToString() + "','" + g1.Cells[6].FormattedValue.ToString() + "','" + TotalTaxtxt.Text + "','" + totalamounttxt.Text + "')", con);
con.Open();
cmd.ExecuteNonQuery();
MessageBox.Show("Records Inserted SuccessFully");
con.Close();
}
Nitin Sontakke9y ago
BillNo is integer in database. So please be consistent.

I suggest following:
private int billno(string p)
{
  Int32 Billno = 0;
  cmd = new SqlCommand(p, con);
  con.Open();
  Billno = (Int32) cmd.ExecuteScalar();
  con.Close();
  return Billno;
}
Gnanavel Sekar9y ago
Hi Jyoti,

private string billno(string p)
{
string Billno = "0";
cmd = new SqlCommand(p, con);
con.Open();
SqlDataReader reader = cmd.ExecuteReader();
if (reader.Read())
{
Billno = reader[0].ToString();
}
reader.Close();
return Billno;
con.Close();
}

private void btn_Insert_Click(object sender, EventArgs e)
{
string Billno = billno(Convert.ToString("Select ISNULL(Max(Billno+1),1) From MainBillForm"));
}

if you are getting number in reader[0] means use below one,

private int billno(int p)
{
int Billno = 0;
cmd = new SqlCommand(p, con);
con.Open();
SqlDataReader reader = cmd.ExecuteReader();
if (reader.Read())
{
Billno = Convert.Toint32(reader[0].ToString());
}
reader.Close();
return Billno;
con.Close();
}
private void btn_Insert_Click(object sender, EventArgs e)
{
int Billno = billno(Convert.Toint32("Select ISNULL(Max(Billno+1),1) From MainBillForm"));
}
Karthi Keyan9y ago
string Billno = billno("Select ISNULL(Max(Billno+1),1) From MainBillForm");

change int to string.
Jyoti Jodha9y ago
Now Error Show in

int Billno = billno("Select ISNULL(Max(Billno+1),1) From MainBillForm");
Nitin Sontakke9y ago
Change from

private int billno(string p)

to

private String billno(string p)

cannot implicitly convert type 'string' to 'int' in c#

Nitin Sontakke

Gnanavel Sekar

Karthi Keyan