关于数据库数据日期日期批量修改

Question

表名：spycd
列名：RQ(A) YSRQ(B)将B列的日期修改为A列日期减1，比如：第一行将B列中2011-03-28 改为2010-09-19         RQ                                 YSRQ
2010-09-20 00:00:00.000             2011-03-28 00:00:00.000
2010-09-29 00:00:00.000             2011-03-28 00:00:00.000
2010-10-03 00:00:00.000             2011-03-28 00:00:00.000
2010-10-22 00:00:00.000             2011-03-28 00:00:00.000
2010-10-26 00:00:00.000             2011-03-28 00:00:00.000

Answer 1

update tab set b=dateadd(day,-1,a)

Answer 2

update tb 
set b = dateadd(dd,-1,a)

Answer 3

update spycd set YSRQ=dateadd(dd,-1,RQ)

Answer 4

update tab set YSRQ=dateadd(dd,-1,RQ)

Answer 5

update spycd set YSRQ=dateadd(day,-1,'RQ')