SQL Server和Access分别可取得随机记录

withtk_querydo

begin

Close;

sql.clear;

sql.Add("selecttop"+inttostr
(st_count)+"tk.ID,标准答案from题库表tk");

sql.Add("wherepidisnullandtk.题型=
"+quotedstr(tx)+"andtk.知识点="+quotedstr(zsd));

sql.add("andtk.难易度="+quotedstr(nyd)+
"andtk.课程号="+quotedstr(kcdm)+"orderbynewid()");

Open;

end;

functionTTest_Srv_RDataForm.Get_Random_ID
(constkcdm,tx,zsd,nyd,t_count:string):string;

var

sl:TStrings;

i,ii,kk:integer;

begin

try

Result:="";

sl:=TStringList.Create;

withTADOQuery.Create(nil)do

begin

try

Connection:=Adoconnection1;

SQL.Text:="selectIDfrom题库表
wherepidisnulland题型="+quotedstr(tx)+

"and知识点="+quotedstr(zsd)+"and难易度="+quotedstr(nyd)+

"and课程号="+quotedstr(Kcdm);

Open;

whilenotEofdo

begin

sl.Add(Fields[0].AsString);

Next;

end;

Close;

finally

Free;

end;

end;//endwith....

ifsl.Count=0then

Exit;

fori:=0toStrToIntDef(t_count,0)-1do

begin

kk:=sl.Count;//随机因子

Randomize;

ii:=Random(kk);//取得随机数

ifResult=""then

Result:=sl.Strings[ii]

else

Result:=Result+","+sl.Strings[ii];

sl.Delete(ii);
//为了避免有可能出现的重复，此ID被抽取过后把它删了

ifsl.Count=0then
//如果无题可抽了退出循环

Break;

end;

Result:="("+Result+")";
//给结果串前后加上(......)，最终形成(24,36,5,89,72,3,6,1....)的串样

finally

sl.Free;



end;

end;

//=================课程号,题型,知识点,难易度,题量

functionTTest_Srv_RDataForm.Get_Random_Sql
(constkcdm,tx,zsd,nyd,t_count:string):string;

begin

Result:=Get_Random_ID(kcdm,tx,zsd,nyd,t_count);

ifResult<>""then

Result:="selecttop"+t_count+"tk.ID,
标准答案from题库表tkwhereidin"+Result

else

Result:="selecttop"+t_count+"tk.ID,
标准答案from题库表tkwhere1=1";

end;

//以下为调用上述函数生成随机抽题的代码片断

.......

withtk_querydo

begin

Close;

sql.Clear;

sql.Text:=Get_Random_Sql(Kcdm,tx_str,zsd_str,nyd_str,txzsd_count_str);

Open;
end;