在数据窗口画板上的design菜单项下的distinct是做什么用的......

[neveramo]

在数据窗口画板上的design菜单项下的distinct是做什么用的.
哪位朋友知道哪儿可以下载比较好的做帮助系统的软件。
谢谢！

[fzymr]

去掉重复的数据
如有temp表中数据如下：
aa bb
1 1
1 1
2 1

select aa,bb from temp ； 数据如上
如果用了distinct
select distinct aa,bb from temp ;数据如下

aa bb
1 1
2 1

[yzqb]

某列的相同的值只取一个

[yzqb]

/*以下的代码写在rowsfocuschanged 事件中，目的是要将图象从SQl Server 数据库中读出显示在DW_1的P_1中可是Retrieve()能读出并显示，当移动到下一行就报内存错误，Pb7.03,请帮忙解决或提供更好的方法*/

String ryid,f,t
blob b
integer li_f
Boolean flag=True
//FileDelete("c:\temp\pic.jpg")
dw_1.object.P_1.filename = ""
ryid=dw_1.getitemstring(dw_1.getrow(),"ryid")
SELECTBLOB pic INTO :b
FROM t_dwry WHERE ryid = :ryid;
if len(b) > 0 then
li_f = FileOpen(ryid+ ".jpg",StreamMode!,Write!,LockWrite!,Replace!)
FileWrite(li_f,b)
FileClose(li_f)
f=ryid+ ".jpg"
t="c:\temp\pic.jpg"
if CopyFileA(f,t,flag) then// CopyFileA 为声明的API函数
dw_1.object.P_1.filename = "c:\temp\pic.jpg"
end if
end if

[yzqb]

http://www.csdn.net/expert/topic/565/565207.xml?temp=.3335535

[neveramo]

谢谢！
但是为什么以前检索数据窗口时，都没问题，现在却提示说"data-conversion resulted overflow",不过执行一下distinct就没问题了。

[liulee]

可能你的表结构改变了。
把你的数据窗的sql语法重新做一次。

[neveramo]

数据窗口里面用了两个表里的字段，这两个表里有一个相同的字段相关联，并且两个表里都有相同的相对应的数据，但是检索的时候，却没有数据。
这是为什么？

[programmerwei]

你在数据窗口sql的where中设定了吗？可否将你的sql粘出来。

[sorrow_arrow]

但是在两个表中都是等于相同字段的值却没有，当然检索不出来了

[neveramo]

SQL语句如下：
SELECT pgb_ysgzbzk.cust,
pgb_ysgzbzk.bh,
pgb_ysgzbzk.ptno,
pgb_ysgzbzk.cpwl,
pgb_ysgzbzk.bmys,
pgb_ysgzbzk.syjys,
pgb_ysgzbzk.zdjys,
pgb_ysgzbzk.ddys,
pgb_ysgzbzk.sydd,
pgb_ysgzbzk.yydd,
pgb_ysgzbzk.zjcavs,
pgb_ysgzbzk.flcavs,
pgb_ysgzbzk.hxhgsj,
pgb_ysgzbzk.hxhgwd,
pgb_ysgzbzk.hwxhgsj,
pgb_ysgzbzk.hwxhgwd,
pgb_ysgzbzk.lcgx1,
pgb_ysgzbzk.lcgx2,
pgb_ysgzbzk.lcgx3,
pgb_ysgzbzk.lcgx4,
pgb_ysgzbzk.lcgx5,
pgb_ysgzbzk.lcgx6,
pgb_ysgzbzk.lcgx7,
pgb_ysgzbzk.lcgx8,
pgb_ysgzbzk.lcgx9,
pgb_ysgzbzk.lcgx10,
pgb_ysgzbzk.lcgx11,
pgb_ysgzbzk.lcgx12,
pgb_ysgy.bms1,
pgb_ysgy.bms2,
pgb_ysgy.bms3,
pgb_ysgy.bms4,
pgb_ysgy.bms5,
pgb_ysgy.bms6,
pgb_ysgy.bms7,
pgb_ysgy.bms8,
pgb_ysgy.bm11,
pgb_ysgy.bml11,
pgb_ysgy.bm12,
pgb_ysgy.bml12,
pgb_ysgy.bm13,
pgb_ysgy.bml13,
pgb_ysgy.bm14,
pgb_ysgy.bml14,
pgb_ysgy.bm15,
pgb_ysgy.bml15,
pgb_ysgy.bm21,
pgb_ysgy.bml21,
pgb_ysgy.bm22,
pgb_ysgy.bml22,
pgb_ysgy.bm23,
pgb_ysgy.bml23,
pgb_ysgy.bm24,
pgb_ysgy.bml24,
pgb_ysgy.bm25,
pgb_ysgy.bml25,
pgb_ysgy.bm31,
pgb_ysgy.bml31,
pgb_ysgy.bm32,
pgb_ysgy.bml32,
pgb_ysgy.bm33,
pgb_ysgy.bml33,
pgb_ysgy.bm34,
pgb_ysgy.bml34,
pgb_ysgy.bm35,
pgb_ysgy.bml35,
pgb_ysgy.bm41,
pgb_ysgy.bml41,
pgb_ysgy.bm42,
pgb_ysgy.bml42,
pgb_ysgy.bm43,
pgb_ysgy.bml43,
pgb_ysgy.bm44,
pgb_ysgy.bml44,
pgb_ysgy.bm45,
pgb_ysgy.bml45,
pgb_ysgy.bm51,
pgb_ysgy.bml51,
pgb_ysgy.bm52,
pgb_ysgy.bml52,
pgb_ysgy.bm53,
pgb_ysgy.bml53,
pgb_ysgy.bm54,
pgb_ysgy.bml54,
pgb_ysgy.bm55,
pgb_ysgy.bml55,
pgb_ysgy.bm61,
pgb_ysgy.bml61,
pgb_ysgy.bm62,
pgb_ysgy.bml62,
pgb_ysgy.bm63,
pgb_ysgy.bml63,
pgb_ysgy.bm64,
pgb_ysgy.bml64,
pgb_ysgy.bm65,
pgb_ysgy.bml65,
pgb_ysgy.bm71,
pgb_ysgy.bml71,
pgb_ysgy.bm72,
pgb_ysgy.bml72,
pgb_ysgy.bm73,
pgb_ysgy.bml73,
pgb_ysgy.bm74,
pgb_ysgy.bml74,
pgb_ysgy.bm75,
pgb_ysgy.bml75,
pgb_ysgy.bm81,
pgb_ysgy.bml81,
pgb_ysgy.bm82,
pgb_ysgy.bml82,
pgb_ysgy.bm83,
pgb_ysgy.bml83,
pgb_ysgy.bm84,
pgb_ysgy.bml84,
pgb_ysgy.bm85,
pgb_ysgy.bml85,
pgb_ysgy.ysdz,
pgb_ysgzbzk.gx,
pgb_ysgy.yys,
pgb_ysgy.yyf1,
pgb_ysgy.yyfl1,
pgb_ysgy.yyf2,
pgb_ysgy.yyfl2,
pgb_ysgy.yyf3,
pgb_ysgy.yyfl3,
pgb_ysgy.yyf4,
pgb_ysgy.yyfl4,
pgb_ysgy.yyf5,
pgb_ysgy.yyfl5,
pgb_ysgy.sys,
pgb_ysgy.syf1,
pgb_ysgy.syfl1,
pgb_ysgy.syf2,
pgb_ysgy.syfl2,
pgb_ysgy.syf3,
pgb_ysgy.syfl3,
pgb_ysgy.syf4,
pgb_ysgy.syfl4,
pgb_ysgy.syf5,
pgb_ysgy.syfl5
FROM pgb_ysgzbzk,
pgb_ysgy
WHERE ( pgb_ysgzbzk.ptno *= pgb_ysgy.ptno) and
( ( pgb_ysgzbzk.ptno = :zdxh ) )

两个表中都是等于相同字段的记录有好多呢，就是检索不出来

[programmerwei]

如果pgb_ysgzbzk中的记录多于pgb_ysgy的话 应改为：
pgb_ysgzbzk.ptno = pgb_ysgy.ptno(+)