大家帮我看看吧,错在哪儿?

[guiyings]

我在数据窗口中放了一个ddlb_1,用它来检索,写成如下代码老报错如下:
string techid , ls_techname
ls_techname = trim(string(ddlb_4.text))
if ls_techname = '' then
messagebox("提示","请输入内容!")
return
end if

select TechID into :techid from Techname where mytechname =:ls_techname;
messagebox("",techid)
dw_3.setsqlselect("select model,sect,state,parameter,time,modifytime,createtime,techid from techdata where TechID = techid")
dw_3.settransobject(sqlca)
dw_3.retrieve()

可是我要是把代码改为如下:
string techid , ls_techname
ls_techname = trim(string(ddlb_4.text))
if ls_techname = '' then
messagebox("提示","请输入内容!")
return
end if

select TechID into :techid from Techname where mytechname =:ls_techname;
messagebox("",techid)
dw_3.setsqlselect("select model,sect,state,parameter,time,modifytime,createtime,techid from techdata where TechID ='21151EE58B1043D2BA8D15F36542D31F'")
dw_3.settransobject(sqlca)
dw_3.retrieve()
一点错误也没有,可以运行.请问,我上面的错误出在哪儿,如何改对呀?

[TIGERWONG]

兰兰!我来晚一步!!
下次又问题我在解答!!

[guiyings]

说错了,是放了ddlb_4.上面的代码我写在ddlb_4的selectionchanged事件中的.谁能告诉我,错在哪儿?

[csdsjkk]

dw_3.setsqlselect("select model,sect,state,parameter,time,modifytime,createtime,techid from techdata where TechID = techid")
这样写：
dw_3.setsqlselect("select model,sect,state,parameter,time,modifytime,createtime,techid from techdata where TechID ='"+ techid + "'")

[冷箫轻笛]

楼上的正解！不过
为什么不用数据窗口的参数
而在这个地方更改检索条件那？

[xingxing]

你那个仅仅上一个串，不是一个字段

[happy_0325]

dw_3.setsqlselect("select model,sect,state,parameter,time,modifytime,createtime,techid from techdata where TechID = techid")
改为

dw_3.setsqlselect("select model,sect,state,parameter,time,modifytime,createtime,techid from techdata where TechID = '"+techid+"'")

[double22822]

1.大家说得对
2.第一个判断最好加一个or isnull()

[runsoft]

来晚了。SQL表达式有问题。

[liujiaqiang]

哎,兰兰,你怎么又搞错了呢?
你这样吧:

string techid , ls_techname

ls_techname = trim(string(ddlb_4.text))
if ls_techname = '' then
messagebox("提示","请输入内容!")
return
end if

select TechID into :techid from Techname where mytechname =:ls_techname;
messagebox("",techid)
if isnull(techid) or trim(techid) = '' then
return
en if

dw_3.setsqlselect("select model,sect,state,parameter,time,modifytime,createtime,techid from techdata where TechID = techid") //你就错在这个SQL语句上

dw_3.setsqlselect("select model,sect,state,parameter,time,modifytime,createtime,techid from techdata where TechID ='"+ techid + "'") //这样就可以了,techid是变量,不是字段,下次请记住这些小错误!!!

dw_3.settransobject(sqlca)
dw_3.retrieve()

多联系.......

[athere_08]

记住用sqlca,sqlcode来判断执行的结果总是一个好的办法。
或者看关键函数的返回值
蹭一点分，呵呵````