MYSQL delete执行异常Column 'PID' in where clause is ambiguous

MYSQL delete执行错误Column 'PID' in where clause is ambiguous
delete a,b, from a,b where PID in (6,7,8);

两个表中都有PID字段，A.PID是主键，B.PID是无符号int字段记录此数据属于A表哪个主键。我想用上面的命令删除a,b两表中，所有PID值为6,7,8的数据行，结果失败了。。请问正确语句是什么？

[解决办法]
查询分析器分不清pid是哪个表的 如果你两个表都要 请在where条件当中明确你的条件
[解决办法]
delete a,b, from a,b where a.PID in (6,7,8);
[解决办法]
delete a,b from a,b where a.pid in(6,7,8);
[解决办法]
DELETE a,b FROM a,b WHERE a.pID IN (6,7,8);
[解决办法]