我一直在输入相同的username
,但它仍然保存到DB。我的代码出了什么问题?
sql = "INSERT INTO testing_mysql_vb(id,user_name) VALUES(NULL,'" & TextBox1.Text & "')"
Try
dbcomm = New MySqlCommand(sql, dbconn)
dbread = dbcomm.ExecuteReader()
dbread.Close()
If dbread.HasRows Then
sql = "select from testing_mysql_vb where user_name = '" & TextBox1.Text & "'"
MsgBox("Duplicate record!")
End If
Catch ex As Exception
MsgBox("Error in saving to Database. Error is :" & ex.Message)
dbread.Close()
Exit Sub
End Try
MsgBox("The User Name was saved.")
TextBox1.Text = ""
答案 0 :(得分:0)
我可以看到可能存在两个问题: