If not CURSORS ?

I have a requirement to check a value which MUST be unique forever even if it is removed and readded.I have created a seperate table to maintain this value.

Without using a cursor how would I be able to append a duplicate base value (i.e. smith.j@.here.now) with the next sequential value (i.e. smith.j02@.here.now)

Any takers?

Oh ya, These values are not manually entered but populated through a DTS script. The existing values are repopulated from historic tables and new entries are added automatically. Initially the values would be populated without a number but a number needs to be generated on duplicates.Concatenate the datetime(getdate()) down to 1/1000 second. I am sure it will be unique. That's most of the spam mailers do when they create a fake ID to get around your blocking.|||Better yet, concatenate newid(). That will guarantee you a unique value all the time.|||Originally posted by joejcheng
Better yet, concatenate newid(). That will guarantee you a unique value all the time.

It also has to be sequential, not just unique|||You can use substring and max functions to achieve the same sequentially.|||You can't do this with sequential values if you insist on the stipulation that a record can be removed from the database and readded at another time. Even using a cursor to find out that smith.j02@.here.now, smith.j03@.here.now, and smith.j04@.here.now already exist, there is simply no way to know whether smith.j05@.here.now was not previously created and deleted. You have to store the used values permanently somewhere.|||...if you create a table with two columns:

EMailPrefix varchar(50),
EMailIncrement int

...to store both parts of the e-mail address, it is a simple matter to

select EMailPrefix + cast(Max(EMailIncrement) + 1 as NewEMail from UsedEmails where EMailPrefix = @.NewSubscriber group by EMailPrefix

...to get a new unused E-mail variation. Not sure if the syntax above is correct, but you get the picture...|||Unfortunately it is possible that more than one new entry can be made in the same import. (i.e. smith.j exists and two more smith.j are imported).

The list of historic values are being saved in a seperate table as described without the "EMailIncrement int" field. I had considered your exact solution but did not know how to increment 2 newly added values with different increments.

Originally posted by blindman
...if you create a table with two columns:

EMailPrefix varchar(50),
EMailIncrement int

...to store both parts of the e-mail address, it is a simple matter to

select EMailPrefix + cast(Max(EMailIncrement) + 1 as NewEMail from UsedEmails where EMailPrefix = @.NewSubscriber group by EMailPrefix

...to get a new unused E-mail variation. Not sure if the syntax above is correct, but you get the picture...

Unfortunate|||Use a cursor in combination with the table of historical values.

Identy Number

I am using an Identy number to generate a Unique ID for records.
The process is
a. Save header record (identy ID created)
b. Retrieve Identy No using a select statement via odbc
c. Dave many data recors with Identy Number as reference to the Header
Record.
How can i retrieve the Identy No with a select statement.
Regards
Jeff
--
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.583 / Virus Database: 369 - Release Date: 10/02/2004Use the SCOPE_IDENTITY() function.
--
David Portas
SQL Server MVP
--|||To expand David's response... Use a select that returns the identity ie
select @.@.scope_identity
Wayne Snyder, MCDBA, SQL Server MVP
Computer Education Services Corporation (CESC), Charlotte, NC
www.computeredservices.com
(Please respond only to the newsgroups.)
I support the Professional Association of SQL Server (PASS) and it's
community of SQL Server professionals.
www.sqlpass.org
"Jeff Williams" <jeff.williams@.hardsoft.com.au> wrote in message
news:OHc5aqz8DHA.2308@.TK2MSFTNGP11.phx.gbl...
> I am using an Identy number to generate a Unique ID for records.
> The process is
> a. Save header record (identy ID created)
> b. Retrieve Identy No using a select statement via odbc
> c. Dave many data recors with Identy Number as reference to the Header
> Record.
> How can i retrieve the Identy No with a select statement.
> Regards
> Jeff
>
> --
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.583 / Virus Database: 369 - Release Date: 10/02/2004
>

Identy Number

I am using an Identy number to generate a Unique ID for records.
The process is
a. Save header record (identy ID created)
b. Retrieve Identy No using a select statement via odbc
c. Dave many data recors with Identy Number as reference to the Header
Record.
How can i retrieve the Identy No with a select statement.
Regards
Jeff
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.583 / Virus Database: 369 - Release Date: 10/02/2004Use the SCOPE_IDENTITY() function.
David Portas
SQL Server MVP
--|||To expand David's response... Use a select that returns the identity ie
select @.@.scope_identity
Wayne Snyder, MCDBA, SQL Server MVP
Computer Education Services Corporation (CESC), Charlotte, NC
www.computeredservices.com
(Please respond only to the newsgroups.)
I support the Professional Association of SQL Server (PASS) and it's
community of SQL Server professionals.
www.sqlpass.org
"Jeff Williams" <jeff.williams@.hardsoft.com.au> wrote in message
news:OHc5aqz8DHA.2308@.TK2MSFTNGP11.phx.gbl...
> I am using an Identy number to generate a Unique ID for records.
> The process is
> a. Save header record (identy ID created)
> b. Retrieve Identy No using a select statement via odbc
> c. Dave many data recors with Identy Number as reference to the Header
> Record.
> How can i retrieve the Identy No with a select statement.
> Regards
> Jeff
>
> --
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.583 / Virus Database: 369 - Release Date: 10/02/2004
>sql

Identity question

I have two fields that I am concerned with be unique.

Id, and Name.

The id is set to the primary key which automatically makes it unique. How would I set the Name to be unique as well?You add a constraint to it. And making it a primary key doesn't make it an identity. That's yet another type of constraint you apply to it. :)|||Ok here is the example

create table tester(a varchar primary key, b varchar(20) unique);

insert into tester values ('1','2');
insert into tester values ('1','2');
insert into tester values ('2','2');

the first insert statement inserts perfectly, and there will be errors with the second and third statement as a is primary key and is unique and second b is unique. so only first statement gets inserted in to the table.|||Ok, so I cannot specify it at the table level. It must be set at time of insert?|||You can check the uniqueness of the field when u try to insert or update the record/data. with data i think the table is useless.

So the concept of uniqueness comes when u r trying to do some transactions with the table right.

Phani...|||You DO specify it at the table level, either when issuing a CREATE or ALTER table statement.|||Is there any way to do it via Enterprise Manager. I've already created the tables.|||Yes. Check out the"Creating a Unique Constraint" article in MSDN (also in Books Online). It provdes step-by-step instructions. You might actually need a Unique Index instead (follow the link in the article for more information).

Terri|||I actually figured it out late last night, this article is exactly what I did.

Thanks for the help guys.

Identity or unique identifier

Hi there,
I'm new to sql server. I've created a table which can be updated through an aspx form. However coming from an access background I don't know how to generate an auto number. I've read through a number of the threads on here and keep coming across Identity or unique identifier. However I can't actually find out how to implement these.
Any help would be great
Cheers
StuFor Identity columns you need to set the IsIdentity property to "Yes" under Identity Specification in the design view of the table. You then set the Identity seed which is the increment you want to have for each value (usually 1).
For Uniqueidentifiers ( I have not used them until now though I have worked on systems that have used them) you could use the NEWID() function.
Check out books on line for more info. Both have performance/efficiency issues that you need to understand before you implement them.|||Thats brill thanks very much for your response.
All the best
Stu

Identity / Auto Incrementing Column

Hi,

I have an auto incrementing int column setup which serves as my unique primary key. Just wondering what happens when the auto increment reaches the limit? Will it recycle numbers from the begining (who's rows have obviously been deleted by this stage)?

trenyboy wrote:

Hi,

I have an auto incrementing int column setup which serves as my unique primary key. Just wondering what happens when the auto increment reaches the limit? Will it recycle numbers from the begining (who's rows have obviously been deleted by this stage)?

since int's maximum size is 2G once it's limit is exceeded you will have an arithmetic overflow. same goes with bigint.. although by then 2GB of rows this is a prime candidate for partioning already...