select 语句中变量赋值问题

[shorthair]

start_day,i：tdate.
i:=start_day;
我想利用SELECT语句实现当数据库表中某一记录的值等于 i的值时把该记录找出来。

[lwp_lwp]

Var
I: TDate;
TableName: String;
Begin
Begin
query1.SQL.Clear;
query1.SQL.Add('Select * From '+TableName);
query1.SQL.Add('Where Start_Day = :day');
query1.ParamByName('dqy').AsDateTime := I;
query1.Open;
End;

[shorthair]

真的很感谢各位，本来抱着试一试的心理来这里请教，想不到还真得到了答案，我是DELPHI新手，看来我加入这个栏目是对的。全都给分！

[chll]

query.add('select * from tablename where start_day='''+datetostr(i)+'''');

[xzisgood]

mydate:tdatetime;
mydate:=datetime(i,'12:00:00')
query1.sql.add('select * from tablename where datdiff(day,FieldName,:mydate)';

[zsr]

const
s:= 'select * from %s where xxx=:thedate'
var
thedate:tdatetime;

query1.close;
thedate:=datetime(i,'12:00:00')
query1.sql.add(Format(s,[tablename,thedate]);
query1.open;

[Scarlette]

Var
I: TDate;
TableName: String;
Begin
With Query1 Do
Begin
SQL.Clear;
SQL.Add('Select * From '+TableName);
SQL.Add('Where Start_Day = :Start_Day');
ParamByName('Start_Day').AsDateTime := I;
Open;
End;
End;

[lmpeel]

Var
I: TDate;
TableName: String;
Begin
With Query1 Do
Begin
SQL.Clear;
SQL.Add('Select * From '+TableName);
SQL.Add('Where Start_Day = :Start_Day');
Prepared ; //最好加上这一句
ParamByName('Start_Day').AsDateTime := I;
Open;
End;
End;