如何检查数据库中是否存在值并显示消息 [英] How to check if value exists in database or not and show a message

问题描述

private void btnSearch_Click(object sender, EventArgs e)
        {


            if (searchtext.Text == "")
            {
                MessageBox.Show("Plese Inter Employee's ID you are searching for");
                searchtext.Focus();
            }
            else
            {
                
                OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\\Employees.mdb");
                OleDbDataAdapter ad = new OleDbDataAdapter("select * from Employee where EmpID=@EmpID", con);
                ad.SelectCommand.Parameters.Add("@EmpID", OleDbType.Integer);
                ad.SelectCommand.Parameters["@EmpID"].Value = int.Parse(searchtext.Text);


                DataSet ds = new DataSet();
                ad.Fill(ds, "Emp");
                DGV1.DataSource = ds.Tables["Emp"];

               
                if (ds == null)
                {
                    
                    MessageBox.Show("not found!!");

                }
                else
                {
                   MessageBox.Show("The Employee you are searching for is listed down, if you want to update the data click the arrow sign on the lift side of the record");
                }
            }

推荐答案

试试

Try

if(ds.Tables["Emp"].Rows.Count>0)
{
   MessageBox.Show("Found !!");
}
else
{
   MessageBox.Show("not found!!");
}

尝试类似

If（ds.Tables [0] .HasRows）

发现消息员工

Try something like
If(ds.Tables[0].HasRows)
Message employee found

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