如何在此代码中添加验证(检查数据库中是否存在值) [英] How To Add validation( check if value exists in database) in this code
本文介绍了如何在此代码中添加验证(检查数据库中是否存在值)的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
SqlConnection sqlcon = new SqlConnection(@"Server=ADMIN-PC\SQLEXPRESS;Database=ELMANAR; Integrated Security = True");
SqlDataAdapter da;
DataTable dt1 = new DataTable();
Data_Access_Layer.DataAccessLayer DAL = new Data_Access_Layer.DataAccessLayer();
SqlCommand cmd = new SqlCommand();
private void btnsave_Click(object sender, EventArgs e)
{
try
{
cmd.CommandType = CommandType.Text;
cmd.Connection = sqlcon;
cmd.CommandText = "insert into TBL_CATEGORYCUSTOMERS (catcustomer_id,catcustomer_name,catcustomer_note) values ('" + txtid.Text + "','" + txtname.Text + "','" + txtnote.Text + "')";
sqlcon.Open();
cmd.ExecuteNonQuery();
MessageBox.Show("Saved");
sqlcon.Close();
dt1.Clear();
da.Fill(dt1);
btnsave.Enabled = false;
btnadd.Enabled = true;
txtid.Clear();
txtname.Clear();
txtnote.Clear();
}
catch { }
推荐答案
要检查值是否存在,请使用Select语句。首先运行SELECT语句,检查返回值,然后根据需要继续。
To check if a value exists then you use a Select statement. Just run the SELECT statement first, check the return value, then proceed as you need to.
要检查值是否存在,请使用Select语句。只需先运行SELECT语句,检查返回值,然后根据需要继续。
谢谢你但是
我该怎么做
To check if a value exists then you use a Select statement. Just run the SELECT statement first, check the return value, then proceed as you need to.
thank you but
How Can I do that
这篇关于如何在此代码中添加验证(检查数据库中是否存在值)的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文