) INSERT MyTable (Col1, Col2) VALUES (DEFAULT, 'cde'), (DEFAULT, 'xyz') SELECT * FROM MyTable Col1 Col2 PRIMARY KEY NONCLUSTERED DEFAULT (NEXT VALUE FOR MySequence), CREATE SEQUENCE MySequence AS INT START WITH 1 INCREMENT BY 1 The following example creates sequence and uses it for a primary key default.
#Postgresql serial series
You can share value series among columns and tables.Įasier management, restart, and modification of sequence properties.Īllows assignment of value ranges using sp_sequence_get_range and not just per-row values. You can use SEQUENCE objects to obtain a value before the actual INSERT takes place. SEQUENCE objects provide several advantages over IDENTITY columns: For example, a SEQUENCE value can be used as a default value for a surrogate key column. You can retrieve a value from a SEQUENCE object using the NEXT VALUE FOR function. Multiple tables and multiple columns from the same table may use the values from one or more SEQUENCE objects. You can manage sequences using the ALTER SEQUENCE statement. Sequences are objects that are independent of a particular table or column and are defined using the CREATE SEQUENCE DDL statement. The following example creates a table with a compound primary key including an IDENTITY column. The following example creates a table with a non-key IDENTITY column and an increment of 10. The following example inserts a row and retrieve the generated IDENTITY value.
The following example creates a table with an IDENTITY column. You can manage IDENTITY columns using the DBCC CHECKIDENT command, which provides functionality for reseeding and altering properties. Applications can obtain IDENTITY values using the SCOPE_IDENTITY, and IDENT_CURRENT functions. The IDENTITY value is generated as part of the transaction that inserts table rows.
Additional constraints such as primary or unique keys, explicit index specifications, or other properties must be specified in addition to the IDENTITY property. The identity property doesn’t enforce uniqueness of column values, indexing, or any other property.
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