update/replace column content

//mySQL

UPDATE [table_name]
set [column_name]=REPLACE([column_name], '[before]', '[after]')


UPDATE s_his
set s_his_date=REPLACE(s_his_date, 'Dec 7, 2011', '2011-12-07')

date calculation

//mySQL


SELECT CURDATE( )
-------------------
CURDATE( )
2011-12-29

SELECT CURDATE( ) -1
-------------------
CURDATE( ) -1
20111228

SELECT now( )
-------------------
now( )
2011-12-29 10:29:31

SELECT now( )-1
-------------------
now( )-1
20111229104426.000000