创建自己的数据库

type

TMember=record

Name:string[50];

eMail:string[30];

Posts:LongInt;

end;

varMembers:array[1..50]ofTMember;

varF:fileofTMember;

writedata

var

F:fileofTMember;

i:integer;

begin

AssignFile(F,'members.dat');

Rewrite(F);

try

forj:=1to50do

Write(F,Members[j]);

finally

CloseFile(F);

end;

end;

readdata

var

Member:TMember

F:fileofTMember;

begin

AssignFile(F,'members.dat');

Reset(F);

try

whilenotEof(F)dobegin

Read(F,Member);

{DoSomethingWithMember;}

end;

finally

CloseFile(F);

end;

end;

seekandposition

{gobacktothebeginning-thefirstrecord}

Seek(F,0);

{gotothe5-threcord}

Seek(F,5);

{Jumptotheend-"after"thelastrecord}

Seek(F,FileSize(F));

changeandupdate

procedureChangeEMail(constRecN:integer;constNewEMail:string);

varDummyMember:TMember;

begin

{assign,open,exceptionhandlingblock}

Seek(F,RecN);

Read(F,DummyMember);

DummyMember.Email:=NewEMail;

{readmovestothenextrecord,wehaveto

gobacktotheoriginalrecord,thenwrite}

Seek(F,RecN);

Write(F,DummyMember);

{closefile}

end;