A.let @n=1
B.set @n=1
C.set n=1
D.select 1 from @n

A.‘2009-5-11’
B.2‘011-5-9’
C.‘2011’
D.2011

A.70
B.1
C.3
D.7

A.’12’
B.12
C.93
D.’93’

A.’123’
B.{123}
C.123
D.[123]

A.[2009-5-11]
B.’2009-5-11’
C.2009-5-11
D.2009/5/11