初学DELPHI,大家来帮帮我~~~~

[如风]

if combobox1.Text='wap' then
Str_database:='wap_Info';
if combobox1.Text='彩信' then
Str_database:='mms_Info';
if combobox1.Text= '彩铃' then
Str_database:='cl_Info';
if combobox1.Text='支持GPRS和MMS' then
Str_database:='gprs_Info';

with DataModule1.ADOQuery1 do
begin
close;
SQL.Clear ;
SQL.Add('select tqhm_tmp.hm,tqhm_tmp.grant_date,:#a,:#b from tqhm_tmp, :#c where tqhm_tmp.hm=:#d');
Parameters.ParamByName('#a').Value := Str_database + '.pp';
Parameters.ParamByName('#b').Value := Str_database + '.qydm';
Parameters.ParamByName('#c').Value := Str_database;
Parameters.ParamByName('#d').Value := Str_database + '.hm';
open;
end;
当运行到open时,弹出一个"必须声明'@p3'变量"的错误,我哪有用什么P3,大家帮帮忙!!

[erhan]

@p3即是你的#c，ado会把你的几个参数依次转换为@p1,@p2,@p3,@p4然后传递给数据库
应该是sql里的表名不支持参数形式传递导致的错误

你的程序可以改成
SQL.Add('select a.hm,a.grant_date,b.pp,b.qydm from tqhm_tmp as a,' + Str_database + ' as b where a.hm=b.hm');