asp中用数据库生成不重复的流水号


            复制代码 代码如下:'************************************************* '函数名：getMaxOrder '作 用：得到最大序列号 '参 数：fieldName ----在序列号表中的字段名 ' tableName ----序列号所在表名 ' fieldName ----在表中的字段名 '返回值：字段的最大值 '调用函数：idAdd：作用见上 '************************************************* function getMaxOrder(fieldName,tableName,tableFileName) dim orderNO,orderRS,testRS set testRS=Server.CreateObject("ADODB.recordset") set orderRS=Server.CreateObject("ADODB.recordset") firstNO=year(date)&right(("0"&month(date)),2) orderSQL="select * from fieldMaxValue where fieldName='"&fieldName&"'" orderRS.open orderSQL,conn,3,2 if not orderRS.eof then orderRS("fieldMaxValue")=orderRS("fieldMaxValue") orderNO=orderRS("fieldMaxValue") if left(orderNO,6)=firstNO then orderNO=idAdd(orderNO) else orderNO=firstNO&"00001" end if else orderRS.addnew orderRS("fieldName")=fieldName orderNO=firstNO&"00001" end if testRS.open "select max("&tableFileName&") from "&tableName&" where "&tableFileName&" like '"&firstNO&"%'",conn,1,2 if (not testRS.eof) and testRS(0).value>orderNO then orderNO=idAdd(testRS(0).value) end if testRS.close set testRS=nothing orderRS("fieldMaxValue")=orderNO orderRS.update orderRS.close set orderRS=nothing getMaxOrder=orderNO end function '************************************************* '函数名：idAdd '作 用：用来增加一：比如idAdd("5")="6",idAdd("L99")="M00"，idAdd("!")="!1" ' 如果是数字就到9后进位,如果是小写字母到期z后进位 ' 如果是大写字母到Z后进位，其它在后面加一个1 '参 数：id ----需来增加的数 '返回值：增加后的数 '调用函数：addOne 一个数增加一 AddOne("5")="6",Add(9)="0",AddOne("a")="b", ' AddOne("z")="a",AddOne("A")="B",AddOne("Z")="A" '************************************************* Function AddOne(first) Dim tempfirst AddOne = first intfirst = Asc(first) If (intfirst >= 48 And intfirst < 57) Or (intfirst >= 65 And intfirst < 90) Or (intfirst >= 97 And intfirst < 122) Then AddOne = Chr(intfirst + 1) Exit Function End If If (intfirst = 57) Then AddOne = "0" Exit Function End If If (intfirst = 90) Then AddOne = "A" Exit Function End If If (intfirst = 122) Then AddOne = "a" Exit Function End If End Function Function idAdd(id) Dim fornt, back, strFind, strBackFind, idLen, tempid if id="" or isNull(id) then iddAdd=1 exit Function end if tempid = id idLen = Len(id) For i = 1 To idLen fornt = Left(id, idLen - i) back = Right(id, i - 1) strFind = Mid(id, idLen + 1 - i, 1) strBackFind = AddOne(strFind) id = fornt & strBackFind & back If strFind < strBackFind Then Exit For End If If strFind > strBackFind Then If i = idLen Then id = id & "1" Else If Mid(id, idLen - i, 1) = AddOne(Mid(id, idLen - i, 1)) Then id = fornt & strBackFind & back & "1" Exit For End If End If End If Next If id = tempid Then id = id & "1" End If idAdd = id End Function '调用示例 serviceNO=getMaxOrder("serviceNO","service","serviceNO") '其中保存所有字段流水号最大值的表的结构为: 表名:fieldMaxValue 字段 id fieldName fieldMaxValue