date time format of t-sql

ktkuo

--- select convert(datetime,(convert(char(7),dateadd(month,-1,getdate()),111)+'/1')) ; last month first day
---select  dateadd(day,-1,convert(datetime,(convert(char(7),getdate(),111)+'/1')))  ; last month end day
---select convert(datetime,(convert(char(7),getdate(),111)+'/1'))   ;  this month first day
---select dateadd(day,-1,convert(datetime,(convert(char(7),dateadd(month,1,getdate()),111)+'/1'))) ; this month end day

---select convert(datetime,(convert(char(7),dateadd(month,1,getdate()),111)+'/1')) ; next month first day


ex: 2011/8/9
---SELECT CONVERT(VARCHAR(4),YEAR(GETDATE()))+'/'+CONVERT(VARCHAR(2),MONTH(GETDATE()))
+'/'+CONVERT(VARCHAR(2),DAY(GETDATE()))