我还想问一下 那个删除语句
delete from mucMessage where roomID in (select roomID from mucRoom where creationDate < a);
delete from mucMemberHistory where roomID in (select roomID from mucRoom where creationDate < a);
delete from mucRoom where creationDate < a;
delete from jiveMessage where creationDate < a;
要删除4个表里的内容, 我只是要删除聊天记录 ,必须都清除这个4个表马 只清除mucMessage不行吗?