{
                MessageBox.Show("请输入完整的商品信息", "信息提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
            else
            {

      sql = "select * from product where number=" + "'" + textBox5.Text.Trim() + "'";
                adapter = new SqlDataAdapter(sql, con);
                adapter.Fill(dataset, "product");
                if (dataset.Tables["product"].Rows.Count == 1)
                { MessageBox.Show("要添加的商品已存在", "信息提示", MessageBoxButtons.OK, MessageBoxIcon.Warning); showproduct(); }

                else
                {
                    sql = string.Format(@"insert into product(number,name,model,category,amount,price,location,maintenance,date,mark)
                   values('{0}','{1}',{2},'{3}','{4}','{5}','{6}','{7}','{8}','{9}')", textBox5.Text.Trim(),
                        textBox6.Text.Trim(), textBox7.Text.Trim(), textBox8.Text.Trim(), textBox9.Text.Trim(),
                        textBox24.Text.Trim(), textBox25.Text.Trim(), textBox26.Text.Trim(), dateTimePicker1.Value, textBox27.Text.Trim());
                    SqlCommand cmd = new SqlCommand(sql, con);
                    try
                    {
                        con.Open();
                        cmd.ExecuteNonQuery();
                        MessageBox.Show("添加成功", "信息提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                        showproduct();
                    }
                    catch { }
                    finally ERP销售管理销售合同子模块的设计与开发(10):http://www.youerw.com/jisuanji/lunwen_2204.html