如何更新在vb.net MySQL数据库

Question

私人小组Button2_Click（BYVAL发件人为System.Object的，BYVALË作为System.EventArgs）把手Button2.Click

Dim remarks As String 
    Dim am_OUT As String = "11:30:01 AM" 


    If LblTime.Text >= am_OUT Then 
     remarks = "OVERTIME" 
    Else 
     remarks = "PRESENT" 
    End If 


    sql = "UPDATE attendance SET am_out=@am_out, noon_remarks=@noon_remarks " & _ 
      "WHERE id_no= '" & Txtid.Text & "'AND date LIKE '" & LblDate.Text & "'and am_out is null" 

    Try 
     With com 
      .Connection = con 
      .CommandText = "SELECT * FROM attendance WHERE id_no LIKE '" & Txtid.Text & "' AND date LIKE '" & LblDate.Text & "'AND am_out is NOT NULL" 

     End With 



     com.Parameters.Add(New MySqlParameter("@am_out", LblTime.Text)) 
     com.Parameters.Add(New MySqlParameter("@noon_remarks", remarks)) 

     com.ExecuteNonQuery() 

     If remarks = "OVERTIME" Then 
      MessageBox.Show("You have little overtime") 
     ElseIf remarks = "PRESENT" Then 
      MessageBox.Show("You Log out on time") 
     End If 




    Catch ex As Exception 
     MsgBox(ex.Message) 
    End Try 
End Sub 

末级

我不能更新我的数据库表中的mysql 和mysql数据库已经有了amin并且是备注

Answer 1

我想对象com是你的MySqlCommand。如果是这种情况下，线

.CommandText = "SELECT * FROM attendance WHERE id_no LIKE '" & Txtid.Text & "' AND date LIKE '" & LblDate.Text & "'AND am_out is NOT NULL" 

是一个SELECT语句，并在执行此命令

说，我建议要正确实现您的查询的每一个部分参数化查询无法更新任何东西，当然，使用正确的语句更新您的记录

sql = "UPDATE attendance SET am_out=@am_out, noon_remarks=@noon_remarks " & _ 
     "WHERE id_no= @id AND date LIKE @dt and am_out is null" 

Try 
    With com 
     .Connection = con 
     .CommandText = sql 
     .Parameters.AddWithValue("@am_out",LblTime.Text) 
     .Parameters.AddWithValue("@noon_remarks",remarks) 
     .Parameters.AddWithValue("@id",Txtid.Text) 
     .Parameters.AddWithValue("@dt",Convert.ToDateTime(LblDate.Text)) 
    End With 
    com.ExecuteNonQuery()