在VB6中用Select语句检索记录 |
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本文向你介绍如何不用借助Access，直接在程序中
缔造一个数据库，
而后从
标准的ASCII文本文件中读取数据到数据库中 。原文是微软
常识库中的一篇文章，但当时是针对VB3写的，所以其中的代码有点
过期 。例如现在DAO中已没有Table对象，代之以Recordset对象 。下面是
批改后的代码，在VB6中调试通过 。 在窗体中增加三个命令按钮和两个MSFlexGrid. 依照下表设置和控件的属性： 控件属性值 Command1Caption" 构建文本文件并显示在网格中" Command2Caption"传输入数据并新建一个数据库" Command3Caption"显示新数据库中的数据" Grid1Cols5 Grid1Rows35 Grid2Cols5 Grid2Rows35 将下面的代码增加到窗体的申明 部分 Dimnums(30)AsLong Dimnames(30)AsString*20 Dimaddresses(30)AsString*25 Dimss_nums(30)AsString*12 ConstDB_LONG=4 ConstDB_TEXT=10 ConstDB_LANG_GENERAL=";LANGID=0x0809;CP=1252;COUNTRY=0" 将下面的代码增加到窗体的Load事件中 SubForm_Load() Show grid1.ColWidth(1)=1000'ForEmpID grid1.ColWidth(2)=2000'ForEmpName grid1.ColWidth(3)=3000'ForEmpAddr grid1.ColWidth(4)=2000'ForEmpSSN grid1.Col=1 grid1.Row=0 grid1.Text="EmpID"'HeaderforEmpIDfromtextfile grid1.Col=2 grid1.Row=0 grid1.Text="EmpName"'HeaderforEmpNamefromtextfile grid1.Col=3 grid1.Row=0 grid1.Text="EmpAddr"'HeaderforEmpAddrfromtextfile grid1.Col=4 grid1.Row=0 grid1.Text="EmpSSN"'HeaderforEmpSSNfromtextfile grid2.ColWidth(1)=1000'ForEmpID grid2.ColWidth(2)=2000'ForEmpName grid2.ColWidth(3)=3000'ForEmpAddr grid2.ColWidth(4)=2000'ForEmpSSN grid2.Col=1 grid2.Row=0 grid2.Text="EmployeeID"'HeaderforEmpIDfromDB grid2.Col=2 grid2.Row=0 grid2.Text="EmployeeName"'HeaderforEmpNamefromDB grid2.Col=3 grid2.Row=0 grid2.Text="EmployeeAddr"'HeaderforEmpIDfromDB grid2.Col=4 grid2.Row=0 grid2.Text="EmployeeSSN"'HeaderforEmpNamefromDB EndSub
Fori=1To30 nums(i)=i names(i)="JohnDoe#" Str$(i) addresses(i)=Str$(i) "MockingBirdLane" Ifi<9Then '*Enterthefollowingfourlinesasone,singleline: ss_nums(i)=Trim$(Str$(i) Trim$(Str$(i)) Trim$(Str$(i)) "-" Trim$(Str$(i 1)) Trim$(Str$(i 1)) "-" Trim$(Str$(i)) Trim$(Str$(i)) Trim$(Str$(i)) Trim$(Str$(i))) Else '*Enterthefollowingtwolinesasone,singleline: ss_nums(i)=Trim$(Trim$(Str$(999)) "-" Trim$(Str$(88)) "-" Trim$(Str$(7777))) EndIf Nexti Open"Testdata.DAT"ForOutputAs#1 Forj=1To30 Print#1,nums(j) Print#1,names(j) Print#1,addresses(j) Print#1,ss_nums(j) Nextj Close#1 Fori=1To30'Displayresultsfromtextfile grid1.Col=1 grid1.Row=i grid1.Text=nums(i)'LoadEmpIDs grid1.Col=2 grid1.Row=i grid1.Text=names(i)'LoadEmpNames grid1.Col=3 grid1.Row=i grid1.Text=addresses(i)'LoadEmpAddrs grid1.Col=4 grid1.Row=i grid1.Text=ss_nums(i)'LoadEmpSSNs Nexti EndSub 在Command2_Click事件中加入下面的代码 SubCommand2_Click() DimnewdbAsDatabase DimnewtbAsRecordset DimnewtdAsNewtabledef DimnewidxAsNewIndex Dimfield1AsNewfield'ForEmpnums Dimfield2AsNewfield'ForEmpnames Dimfield3AsNewfield'ForEmpaddresses Dimfield4AsNewfield'ForEmpss_nums screen.MousePointer=11'Displaythetimetobuild
Setnewdb=CreateDatabase("NEWDB.MDB",DB_LANG_GENERAL)
newtd.Name="Emp_Table"'*Newtablename field1.Name="Emp_ID"'*HoldsEmployeeIDnums() field1.Type=DB_LONG newtd.Fields.Appendfield1 field2.Name="Emp_Name"'*HoldsEmpnames() field2.Type=DB_TEXT field2.Size=20 newtd.Fields.Appendfield2 field3.Name="Emp_Addr"'*HoldsEmployeeaddr() field3.Type=DB_TEXT field3.Size=25 newtd.Fields.Appendfield3 field4.Name="Emp_SSN"'*Holdsempss_nums() field4.Type=DB_TEXT field4.Size=12 newtd.Fields.Appendfield4 newidx.Name="Emp_ID_IDX"'*Youhavetohaveanindex newidx.Fields="Emp_ID" newidx.Primary=True newtd.Indexes.Appendnewidx newdb.TableDefs.Appendnewtd Setnewtb=newdb.OpenRecordset("Emp_Table") Open"Testdata.dat"ForInputAs#1 BeginTrans DoWhileNot(EOF(1)) newtb.AddNew LineInput#1,tmp1$'Retrieveempl_id LineInput#1,tmp2$'Retrieveempl_name LineInput#1,tmp3$'Retrieveempl_addr LineInput#1,tmp4$ newtb("Emp_ID")=Trim$(tmp1$)'Placeinfield1 newtb("Emp_Name")=Trim$(tmp2$)'Placeinfield2 newtb("Emp_Addr")=Trim$(tmp3$)'Placeinfield3 newtb("Emp_SSN")=Trim$(tmp4$)'Placeinfield4 newtb.Update'Savetotable Loop CommitTrans Close#1'Closetextfile newtb.Close'CloseDB'stable newdb.Close'CloseDB screen.MousePointer=0'Setbacktoshowdone EndSub 在Command3_Click事件中加入下面的代码 SubCommand3_Click() DimdbAsDatabase DimtAsRecordset Dimcounter Setdb=OpenDatabase("NEWDB.MDB") Sett=db.OpenRecordset("Emp_Table") counter=1'StartcounteratRow=1 DoUntilt.EOF grid2.Col=1 grid2.Row=counter grid2.Text=t(0)'LoadEmpID grid2.Col=2 grid2.Row=counter grid2.Text=t(1)'LoadEmpName grid2.Col=3 grid2.Row=counter grid2.Text=t(2)'LoadEmpAddr grid2.Col=4 grid2.Row=counter grid2.Text=t(3)'LoadEmpSSN counter=counter 1 t.MoveNext Loop t.Close db.Close EndSub |
