SQL Server 2012 developing a new feature sequence object (Sequence)

Reprint Link: http://www.cnblogs.com/zhangyoushugz/archive/2012/11/09/2762720.html

As we all know, in the previous version of SQL Server, the GUID or identity is generally used as the identifier, but the identity is a table object, can only guarantee the sequence in a table, when we encounter the following situations,

Table 1

Id	Order type	Price
1	Train tickets	200
4	Plane ticket	2000
5	Tickets	600

Table 2

Id	Order type	Price
2	Hotel	400
3	Park tickets	170
6	Rental fee	300

For example, we need to implement ID consistency between multiple tables, and in SQL Server there will be some trouble, usually we will use an extra temp table to map the relationship of these IDs and then take the sequence from it.

Sequence is very early in Oracle, and SQL Server 2012 's sequence function is similar to that of a schema-based object, so it can be called by multiple tables.

The sequence syntax is as follows:

2. CREATE SEQUENCE [schema_name.] Sequence_name
4. [As [Built_in_integer_type | user-defined_integer_type]]
6. [START with <constant>]
8. [INCREMENT by <constant>]
10. [{MINVALUE [ <constant>]} | {NO MINVALUE}]
12. [{MAXVALUE [ <constant>]} | {NO MAXVALUE}]
14. [CYCLE | {NO CYCLE}]
16. [{CACHE [ <constant>]} | {NO CACHE}]
18. [ ; ]

CREATE SEQUENCE [schema_name.] Sequence_name    [as [Built_in_integer_type | user-defined_integer_type]]    [STAR T with <constant>]    [INCREMENT by <constant>]    [{MINVALUE [<constant>]} | {NO MINVALUE}]    [{MAXVALUE [<constant>]} | {NO MAXVALUE}]    [CYCLE | {NO CYCLE}]    [{CACHE [<constant>]} | {NO CACHE}]    [ ; ]

Start with Set start value

Increment by setting the growth interval

Min and Max set minimum and maximum values respectively

Cycle setting is loop

cache specifies settings for caching

SQL Server 2012 developing a new feature sequence object (Sequence) (GO)