求一SQL语句,在线等大家的帮助!
select   *   from   db   where   mc   like   'x% '   or   mc   like   'y% '   or   mc   like   'z% '   and   rq> '2007-01-01 ';这样写出来的语句不执行and后面的条件,如何让OR   和AND条件同时执行呢?这语句应该怎么写?

------解决方案--------------------
select * from db where (mc like 'x% ' or mc like 'y% ' or mc like 'z% ') and rq> '2007-01-01 '
------解决方案--------------------

select * from db where mc like 'x% ' or mc like 'y% ' or mc like 'z% ' and rq> '2007-01-01 '

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select * from db where left(mc,1) in ( 'x ', 'y ', 'z ') and rq> '2007-01-01 '