var i: integer; beginwith query do begin close; sql.clear; sql.add('select sum(colname) as sumcol from tablename'); open; i:= fieldbyanem('sumcol').asinteger; end; end;
楼主说得不清楚,是不是求某字段唯一值的个数啊? 比如1,3,4,2,1 的唯一值个数是4,而不是5,是这样吗?var i: integer; beginwith query do begin close; sql.clear; sql.add('select count(distinct colname) as sumcol from tablename'); open; i:= fieldbyanem('sumcol').asinteger; end; end;
i: integer;
beginwith query do
begin
close;
sql.clear;
sql.add('select sum(colname) as sumcol from tablename');
open;
i:= fieldbyanem('sumcol').asinteger;
end;
end;
比如1,3,4,2,1 的唯一值个数是4,而不是5,是这样吗?var
i: integer;
beginwith query do
begin
close;
sql.clear;
sql.add('select count(distinct colname) as sumcol from tablename');
open;
i:= fieldbyanem('sumcol').asinteger;
end;
end;