超简单 送分了!!! delphi 怎么创建一个foxpro (.dbf)的临时表???delphi 中怎么创建一个foxpro (.dbf)的临时表???有结构相同的N个.dbf文件:id081225.dbf,id081226.dbf,id081227.dbf...select * from id081225.dbf union all
select * from id081226.dbf union all
select * from id081227.dbf
...我想把上面的查询结果生存一个.dbf 的临时表,怎么做?
或者插入到一个现有的.dbf的表里也行.另外:
select * from id081225.dbf union all
select * from id081226.dbf union all
select * from id081227.dbf
where ...可以正常执行,而下面的却出错(下面的写法SQL-SERVER数据库都可以正常执行的呀),
select * from
(
select * from id081225.dbf union all
select * from id081226.dbf union all
select * from id081227.dbf
) a where ...
select * from id081226.dbf union all
select * from id081227.dbf
...我想把上面的查询结果生存一个.dbf 的临时表,怎么做?
或者插入到一个现有的.dbf的表里也行.另外:
select * from id081225.dbf union all
select * from id081226.dbf union all
select * from id081227.dbf
where ...可以正常执行,而下面的却出错(下面的写法SQL-SERVER数据库都可以正常执行的呀),
select * from
(
select * from id081225.dbf union all
select * from id081226.dbf union all
select * from id081227.dbf
) a where ...
可以用 select * from id081225.dbf where 1=2 save to temptable.dbf然后
select * from id081225.dbf union all
select * from id081226.dbf union all
select * from id081227.dbf
...
把最后的结果转入到temptable.DBF表支持简单的SQL命令。
insert into temptable select * from tablename这样可以。
insert into temptable (select * from a union all select * from b)这个命令不支持。select * from ( select * from id081225.dbf )这样的命令DBF不支持。
select * from id081226.dbf union all
select * from id081227.dbf
select * from id081226.dbf union all
select * from id081227.dbf
好像只是逻辑删除,怎么才物理删除呢?我的删除代码:
idxsql.Active:=false;
idxsql.SQL.clear;
idxsql.SQL.add('delete from id_temp.dbf');
idxsql.ExecSQL;上面只是逻辑删除,怎么才物理删除呢?
好像只是逻辑删除,怎么才物理删除呢?我的删除代码:
idxsql.Active:=false;
idxsql.SQL.clear;
idxsql.SQL.add('delete from id_temp.dbf');
idxsql.ExecSQL;上面只是逻辑删除,怎么才物理删除呢?