How do I auto increment
the primary key
in a SQL Server
database table, I\'ve had a look through the forum but can\'t see how.
Perhaps I'm missing something but why doesn't this work with the SEQUENCE object? Is this not what you're looking for?
Example:
CREATE SCHEMA blah.
GO
CREATE SEQUENCE blah.blahsequence
START WITH 1
INCREMENT BY 1
NO CYCLE;
CREATE TABLE blah.de_blah_blah
(numbers bigint PRIMARY KEY NOT NULL
......etc
When referencing the squence in say an INSERT command just use:
NEXT VALUE FOR blah.blahsequence
More information and options for SEQUENCE
You can use the keyword IDENTITY
as the data type to the column along with PRIMARY KEY
constraint when creating the table.
ex:
StudentNumber IDENTITY(1,1) PRIMARY KEY
In here the first '1' means the starting value and the second '1' is the incrementing value.
When you're using Data Type: int you can select the row which you want to get autoincremented and go to the column properties tag. There you can set the identity to 'yes'. The starting value for autoincrement can also be edited there. Hope I could help ;)
Make sure that the Key column's datatype is int
and then setting identity manually, as image shows
Or just run this code
-- ID is the name of the [to be] identity column
ALTER TABLE [yourTable] DROP COLUMN ID
ALTER TABLE [yourTable] ADD ID INT IDENTITY(1,1)
the code will run, if ID
is not the only column in the table
image reference fifo's
If the table is already populated it is not possible to change a column to IDENTITY column or convert it to non IDENTITY column. You would need to export all the data out then you can change column type to IDENTITY or vice versa and then import data back. I know it is painful process but I believe there is no alternative except for using sequence as mentioned in this post.