C#中如何實現編號的自增,明白人請看
給妳個例子參考下:
public string GetAutoDocNo()
{
string DocNo = "AD";
string today = DateTime.Today.Date.ToString("yyyyMMdd", DateTimeFormatInfo.InvariantInfo);
DataSet DocDs = GetDataSet(" select * from News");
//初始化
if (DocDs.Tables[0].Rows.Count == 0)
{
DocNo += today + "101";
return DocNo;
}
/***********************/
else if (DocDs.Tables[0].Rows.Count > 0)
{
int count = 0;
string oldDocNo = string.Empty;
for (int i = 0; i < DocDs.Tables[0].Rows.Count; i++)
{
oldDocNo = DocDs.Tables[0].Rows[i]["NewsID"].ToString();
oldDocNo = oldDocNo.Substring(2, 8);
if (oldDocNo == today) count++;
}
if (count == 0/*當天還沒有單*/)
{
DocNo += today + "1001";//前面有1比較方便，沒有1在後面做的時候要稍微再加幾行代碼
return DocNo;
}
else if (count > 0/*當天已經有單*/)
{
DocDs = GetDataSet("select MAX(CAST(SUBSTRING(NewsID,3,12) AS BIGINT)) as NewsID from News where
(SUBSTRING(NewsID,3,8))='" + today + "'");
string id = DocDs.Tables[0].Rows[0]["NewsId"].ToString();
string lastid = id.Substring(8, 3);
try
{
decimal lastidec = decimal.Parse(lastid);
lastidec += 1;
return DocNo + today + (lastidec.ToString());
}
catch (Exception)
{
throw;
}