请问这种SQL写法会死锁吗？

[shuyisheng]

"update a set
a.box_card_num=b.box_card_num
from tabname_aaa as a,
( select branch_no_belong,card_type_id,out_file_name,branch_no,card_base_id,box_id,count(*) as box_card_num
from tabname_aaa
where bad=0 and addr_flag='N'
group by branch_no_belong,card_type_id,out_file_name,branch_no,card_base_id,box_id
) as b
where a.bad=0 and a.addr_flag='N'
and a.branch_no_belong=b.branch_no_belong
and a.card_type_id=b.card_type_id
and a.out_file_name=b.out_file_name
and a.branch_no=b.branch_no
and a.card_base_id=b.card_base_id
and a.box_id=b.box_id",

[shuyisheng]

这个SQL主要是通过tabname_aaa这张表里通过几个字段来分组groupby然后统计相应的数量，更新到这张表里面的一个字段作为卡数量值。

[卖水果的net]

多个会话，有资源的互相等待，才会有死锁。 你这一个语句，不会有死锁的。