MySQL 如何在vb.net中更新mysql数据库
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how to update mysql database in vb.net
提问by Chris Gee
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) 处理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
End Class
结束类
i cant update my database table in mysql and mysql database already have amin and am remarks
我无法在 mysql 中更新我的数据库表，而 mysql 数据库已经有 amin 和 am 备注
回答by Steve
I suppose that the object comis you MySqlCommand. If this is the case the line
我想这个对象com是你 MySqlCommand。如果是这种情况，线路
.CommandText = "SELECT * FROM attendance WHERE id_no LIKE '" & Txtid.Text & "' AND date LIKE '" & LblDate.Text & "'AND am_out is NOT NULL"
is a SELECT statement and cannot update anything when this command is executed
是一个 SELECT 语句，执行此命令时不能更新任何内容
Said that, I suggest to correctly implement a parameterized query for every part of your query, and, of course, use the correct statement that updates your record
说了这么多，我建议你对查询的每一部分都正确实现参数化查询，当然，使用正确的语句来更新你的记录
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()
