本人在网络编程中遇到几个问题,由于大家用vfp进行网络编程的还很少,所以相关的参考书还不多,只好请教,可能万事开头难吧,对你们来说可能是小菜一碟。还望指教,谢谢!
(一)、
TRY
IF VARTYPE(_SCREEN.ConnectHandle)=="U"
_SCREEN.AddProperty("ConnectHandle")
ENDIF
lnSQLState=SQLEXEC(_SCREEN.ConnectHandle,"")
CATCH
lnSQLState=-1
ENDTRY
疑问有二:
1.try...endtry是什么语句啊?中间的CATCH是其什么作用呀,什么意思?
2. VARTYPE(_SCREEN.ConnectHandle)=="U"
_SCREEN.AddProperty("ConnectHandle")这两句中,VARTYPE是什么函数,"U"是什么意思?
_SCREEN.ConnectHandle是什么句柄啊?怎么以前从来没有见过啊?
(二)、谁见过如下的查询方式:
_SCREEN.SQLString="SELECT tblFix.*,"+;
"tblAsset.AssetName,"+;
"tblAsset.AssetType,"+;
"tblAsset.AssetSet,"+;
"tblAsset.AssetGroup,"+;
"tblAsset.MadeComp,"+;
"tblAsset.MadeDate,"+;
"tblAsset.InDate,"+;
"tblAsset.Price,"+;
"tblAsset.Depart "+;
"FROM tblFix "+;
"INNER JOIN tblAsset "+;
"ON tblFix.AssetNumber=tblAsset.AssetNumber "+cWhere+;
" ORDER BY tblFix.AssetNumber,tblFix.FixDate"
然后执行:
=SQLEXEC(nHandle,_SCREEN.SQLString,"curFix")
这是个综合查询,我能看得懂一些,但是不彻底。