摘要：
SELECT * FROM Billcode_in a LEFT JOIN Billcode_place b ON a.billcode=b.billcode AND b.id=(SELECT MAX(id) FROM Billcode_place WHERE billcode=b.billcode 阅读全文
摘要：
//TextBox 必须是多行文本框 private void Txt_Billcode_KeyDown(object sender, KeyEventArgs e) { if (e.Control && e.KeyCode == Keys.Enter) //当按下Ctrl和Enter 输入回车 { 阅读全文