下面代码是用户点击提交后，先取服务器最大签报编号，然后在此基础上加‘1’，再将新的编号记录写入服务器。
可发生过两个用户同时点击提交，导致编号相同的问题，请问各位老师是如何避免类似的问题的？

-------------------------------------------------------
    *-计算签报编号
    DO CASE      
    CASE ALLTRIM(_WenZ) == "费用"
        _shou = "FY"
    CASE ALLTRIM(_WenZ) == "差旅"
        _shou = "CL"
    CASE ALLTRIM(_WenZ) == "假期"
        _shou = "JQ"
    ENDCASE
    SQLIDLEDISCONNECT(_SQLOA)
    IF SQLEXEC(_SQLOA,"SELECT top 1 QianBBH FROM oa..LiuShui WHERE WenZ = ?_WenZ ORDER BY QianBBH DESC") = 1   &&取服务器当前文种最大签报编号
        SQLIDLEDISCONNECT(_SQLOA)
        IF RECCOUNT() = 0
            _QianBBH = _shou + LEFT(_SendDate,4) + "-00001"
        ELSE
            qbbh = VAL(RIGHT(ALLTRIM(sqlresult.QianBBH),5))
            qbbh = qbbh + 1
            DO CASE
            CASE LEN(ALLTRIM(STR(qbbh))) = 1
                _QianBBH = _shou + LEFT(_SendDate,4) + "-" + "0000" + ALLTRIM(STR(qbbh))
            CASE LEN(ALLTRIM(STR(qbbh))) = 2
                _QianBBH = _shou + LEFT(_SendDate,4) + "-" + "000" + ALLTRIM(STR(qbbh))
            CASE LEN(ALLTRIM(STR(qbbh))) = 3
                _QianBBH = _shou + LEFT(_SendDate,4) + "-" + "00" + ALLTRIM(STR(qbbh))
            CASE LEN(ALLTRIM(STR(qbbh))) = 4
                _QianBBH = _shou + LEFT(_SendDate,4) + "-" + "0" + ALLTRIM(STR(qbbh))
            OTHERWISE
                _QianBBH = _shou + LEFT(_SendDate,4) + "-" + ALLTRIM(STR(qbbh))
            ENDCASE
        ENDIF
    ELSE
        MESSAGEBOX("取签报号失败。",48,"错误信息")
        RETURN
    ENDIF
   
    *-根据标题写各分表
    DO CASE
    *-安全防范费
    CASE _BiaoTi = "安全防范费"
        SQLIDLEDISCONNECT(_SQLOA)
        DO CASE
        CASE LEN(ALLTRIM(_QianBBHCG)) = 0   &&如果 _QianBBHCG 长度等于0，说明是新建签报，分表直接写入
            IF SQLEXEC(_SQLOA,"INSERT INTO oa..aqff (QianBBH,FeiYLX,GongH,XingM,BuM,FeiYHJ,FangFanNR,ShiY) VALUES (?_QianBBH,?_BiaoTi,?_GongHao,?_XingMing,?_BuM_CLR,?_FB0,?_FB1,?_FB2)") < 1
                MESSAGEBOX("写表失败。"+_BiaoTi,48,"错误信息")
                RETURN
            ENDIF
        ENDCASE
    ENDCASE

*-写主流水表新建第一条签报信息
IF SQLEXEC(_SQLOA,"INSERT INTO oa..LiuShui .........

[此贴子已经被作者于2018-7-24 12:28编辑过]

* 用1个专门的编号表来记录编号，
* 或者先插入空数据，读取编号后，更新其他数据
c标记 = sys(2015)
if sqlexec(句柄,'insert into bianhao(编号,标记) select max(编号)+1,?c标记 from bianhao')>0
   sqlexec(句柄,'select 编号,标记 from bianhao where 标记=?c标记','tmp_biaohao')
   ?tmp_biaohao.编号
endif

谢谢老师!

此帖应该对楼主有帮助
https://bbs.bccn.net/viewthread.php?tid=436738&extra=page%3D1%26amp%3Bfilter%3Ddigest

学习中，感谢！

最后解决方法是使用一个专门的编号表来记录编号，运行程序时先从此表取最大编号进行计算，写表时先将编号写入此表，如写入失败，再重新取编号计算再写入，反复几次仍失败则提示后终止运行。