eg:with query1 do begin close; sql.clear; sql.add('select * from table'); execsql; open; end; with quer2 do begin close; sql.clear; sql.add('select * from query1'); execsql; open; end; 整个过程都在程序中实现。运行时会说找不到query1.db
eg:with query1 do begin close; sql.clear; sql.add('create view viewname as select * from table'); execsql; open; end; with quer2 do begin close; sql.clear; sql.add('select * from viewname'); execsql; open; end; 最后别忘了drop view viewname
begin
close;
sql.clear;
sql.add('select * from table');
execsql;
open;
end;
with quer2 do
begin
close;
sql.clear;
sql.add('select * from query1');
execsql;
open;
end;
整个过程都在程序中实现。运行时会说找不到query1.db
Kmh ye ye1 ye2 rq
001 12 22 23 20030101
001 15 16 22 20030103
002 16 78 43 20030103
要求在科目号相同的情况下,求20030101与20030103的ye1,ye2,ye3之差,该如何实现?
begin
close;
sql.clear;
sql.add('create view viewname as select * from table');
execsql;
open;
end;
with quer2 do
begin
close;
sql.clear;
sql.add('select * from viewname');
execsql;
open;
end;
最后别忘了drop view viewname
ye ye1 ye2 rq
12 22 23 20030101
15 16 22 20030103
16 78 43 20030103
求20030101与20030103的ye1,ye2,ye3之差的sql?