select * from announce, board
where announcetopic like '%'
and announce.boardid=board.boardid
and board.boardname like '%园%'
where announcetopic like '%'
and announce.boardid=board.boardid
and board.boardname like '%园%'
调试欢乐多
改为
select announce.* from announce left join board on announce.boardid=board.boardid where announce.topic like '%' and board.boardname like '%园%'