identity 관련
ALTER TABLE gas_station ADD COLUMN ref_id NUMERIC(8,0) IDENTITY
[sybase]identity 속성
http://manuals.sybase.com/onlinebooks/group-as/asg1250e/sqlug/@Generic__BookTextView/19681;pt=19681;uf=0
Chained mode와 unchainde mode
(T-SQL) 서버 측 동적 쿼리에서의 탈출