I have a table already created and need to add an autonumber/ unique identif
ier
field.
If the table already contains records can I just add the new autonumber fiel
d
and run a query to populate this field for all records with unique values?
how do I do this?
are their other ways of doing this ? and how?
thanks
ChrisChris,
When you add and identity column to your table, SQL Server automatically
populates the column. You can not update an identity column.
Example:
use northwind
go
create table t (
colA char(1) not null unique
)
go
insert into t values('a')
insert into t values('b')
insert into t values('c')
go
select * from t
go
alter table t
add colB int not null identity
go
select * from t
go
drop table t
go
AMB
"Chris" wrote:
> I have a table already created and need to add an autonumber/ unique ident
ifier
> field.
> If the table already contains records can I just add the new autonumber fi
eld
> and run a query to populate this field for all records with unique values?
> how do I do this?
> are their other ways of doing this ? and how?
> thanks
> Chris|||I added the unique identifier column using table design.
However when I queried the database the values were all null.
Also since there are a lot of records in the table and generating the
alpha-numeric values does take processing time, I noticed adding the column
did not require any processing, (i.e. no hour glass).
Also I would prefer to just use a big int as it will take up less space and
be faster.
How can I use @.@.identity to update each record? is this possible?
Gracias Alejandro,
Tu eres muy asusto. He vido muchas siertos y respuestas de usted en los
forums.
Perdone mi espanol, estoy apprendiendo.
Por favor, constesta en ingles :)
"Alejandro Mesa" wrote:
> Chris,
> When you add and identity column to your table, SQL Server automatically
> populates the column. You can not update an identity column.
> Example:
> use northwind
> go
> create table t (
> colA char(1) not null unique
> )
> go
> insert into t values('a')
> insert into t values('b')
> insert into t values('c')
> go
> select * from t
> go
> alter table t
> add colB int not null identity
> go
> select * from t
> go
> drop table t
> go
>
> AMB
>
> "Chris" wrote:
>|||As I told you, you can not update an identity column.
AMB
"Chris" wrote:
> I added the unique identifier column using table design.
> However when I queried the database the values were all null.
> Also since there are a lot of records in the table and generating the
> alpha-numeric values does take processing time, I noticed adding the colum
n
> did not require any processing, (i.e. no hour glass).
> Also I would prefer to just use a big int as it will take up less space an
d
> be faster.
> How can I use @.@.identity to update each record? is this possible?
> Gracias Alejandro,
> Tu eres muy asusto. He vido muchas siertos y respuestas de usted en los
> forums.
> Perdone mi espanol, estoy apprendiendo.
> Por favor, constesta en ingles :)
> "Alejandro Mesa" wrote:
>|||okay, so a big int field that has been filled with a value using @.@.identity
can not be edited?
"Alejandro Mesa" wrote:
> As I told you, you can not update an identity column.
>
> AMB
> "Chris" wrote:
>|||I need to create a table with unique primary key on only one field.
How does one create or load a table with unique values in a primary key
field if
you have not been been provided unique values.
I'm happy to use just a big int data type to hold my unique values
"Chris" wrote:
> I have a table already created and need to add an autonumber/ unique ident
ifier
> field.
> If the table already contains records can I just add the new autonumber fi
eld
> and run a query to populate this field for all records with unique values?
> how do I do this?
> are their other ways of doing this ? and how?
> thanks
> Chris|||Correct.
Example:
use northwind
go
create table t (
colA char(1) not null unique
)
go
insert into t values('a')
insert into t values('b')
insert into t values('c')
go
select * from t
go
alter table t
add colB int not null identity
go
select * from t
go
-- this will give an error
update t
set colB = 4
where colB = 2
go
drop table t
go
AMB
"Chris" wrote:
> okay, so a big int field that has been filled with a value using @.@.identit
y
> can not be edited?
>
> "Alejandro Mesa" wrote:
>
Showing posts with label autonumber. Show all posts
Showing posts with label autonumber. Show all posts
Saturday, February 25, 2012
adding identifier number to records
Sunday, February 12, 2012
Adding an autonumber column after the fact?
I have a csv file of quotes. I need to IMPORT the quotes into my SQL Server database. I created the table with an autonumber identity column, but the IMPORT fails because I can't INSERT NULL into my identity column. There is no option to autonumber or anything when I click the TRANSFORM button on the IMPORT wizard. So, I have decided to allow NULLS on the ID column and add the numbering later. I'd rather not have to manually number it, is there a way to do it with a query? I treid just setting it to not allow NULLS and to auto-incrememnt, but that didn't work...I would have asked you to use temp table for the import and then do INSERT INTO a table with IDENTITY SET. Now you do ANSI SQL ALTER TABLE to SET IDENTITY on the table. Run a search of ALTER table in the BOL (books online). Hope this helps.|||Thank-you for your help :)|||I am glad I could help.
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