VFP命令結(jié)構(gòu)與數(shù)據(jù)表的基本操作

1、VFP命令結(jié)構(gòu)與數(shù)據(jù)表的基本操作關(guān)于VFP命令結(jié)構(gòu)命令動(dòng)詞范圍for條件說(shuō)明：1、命令動(dòng)詞List display delete recall pack modify stmcture2、范圍：(4種)1、全部 all2、部分Next部分Rest部分3、單個(gè) record n3、for v 條件條件是邏輯表達(dá)式例如：性別=”男” and身高1.601、命令動(dòng)詞clear dir list display2、范圍(scope)：3、For 條件 復(fù)習(xí)：記錄指針的定位絕對(duì)定位go相對(duì)定位：skip關(guān)于對(duì)數(shù)據(jù)表的操作：1、創(chuàng)建和修改結(jié)構(gòu)構(gòu)造一個(gè)表Creat 表名Modify stmcture (事先

2、要打開(kāi)文件)注意：表的打開(kāi)與關(guān)閉紀(jì)錄指針的定位絕對(duì)定位go top bottom ii相對(duì)定位skip條件定位locate for 邏輯表達(dá)式contmue三個(gè)函數(shù)Recno()記錄號(hào)函數(shù)Bof()文件頭的測(cè)試EofQ文件尾的測(cè)試2、輸入與編輯數(shù)據(jù)Browse編輯于修改數(shù)據(jù)Append添加數(shù)據(jù)3、顯示與查找List for 條件exp LDisplay指針的條件定位命令：Locate for 條件acontinue4、刪除（1）邏輯刪除delete recall（2）物理刪除pack手工操作（交互式操作）5、計(jì)算數(shù)據(jù)表的計(jì)算（1）橫著計(jì)算Replace 字段名with 表達(dá)式（2）豎著計(jì)算 計(jì)

3、數(shù)、求和、平均值6、高級(jí)：排序與索引set defa to e:aaa CREATE PROJECT creat xs modify stmctiue modi stm list appe brow du use學(xué)生 list cleai- du use xs list use學(xué)生 list cleai- list go 2 ? reciioQ dispgo topdispgo bottdisp3skip -1? lecnoQskip 2dispclealist1?bofOskip -1?bofQ go bott?eofQskip 1?eof()skipclealistbrowclealist

4、 foi 性別=“男” list for 身高1.7 list for 計(jì)算機(jī)90 cleai*loca for性別男”contloca for 性別=男dispcontdispcontdisp?eofQlist5dele list pack brow last listcleai- listdele for 性別=”男”lislistrecall alllistset defa to e:aaaduuse學(xué)生listbrowclea use學(xué)生 brow last go 1 disp6 disp skip disp skip -3 ? xecnoQ go top ? recnoQ go bo

5、tt ? recnoQ cleai disp all disp record 45 disp cleai-2disp next 2 ? recnoQ 5disp next 4 3disp rest cleai-crea xsdiiuse xsappebrowmodi stmuse學(xué)生brow lastbrowcleailist for left(姓名,2)=” 李”list for性別i男” and計(jì)算機(jī)70 deallocate for left(姓名,2)=” 李” disp continuedispcontinuedispcontinuedisp?eof()loca for 計(jì)算機(jī)=80

6、dispcontinuedispcontinuedispcontinuedisp?eof()loca for 計(jì)算機(jī)=80?eof()copy to zccleaidelete record 3list1dele next 4listrecall alllistcleadele for另ij=” 男packbrow lastlistdele allpacklistbrow lastappe from zcbrow last計(jì)算：use學(xué)生brow lastreplace all 總分 with 99replace all 平均分 with 97replace all 總分 with 0repl

7、ace all總分with政治+語(yǔ)文+計(jì)算機(jī)replace all平均分with （政治+語(yǔ)文+計(jì)算機(jī)）/3replace all 總分 with 02replace all 總分 with 999replace all 總分 with 02replace 總分 with 999repl for性別=”男”平均分with 100list2disp next 34list next 2cleai-6list rest3list restrepl all總分with政治+語(yǔ)文+計(jì)算機(jī)，平均分witli總分/3 sum計(jì)算機(jī)sum計(jì)算機(jī)to x?xavei計(jì)算機(jī)to p3?P3cleai-aver計(jì)算機(jī)to pn