I've been using MS Access 2000 for a while and have recently switched to MS
SQL 2000. When creating a primary key I am used to MS Access ability to auto
matically enter a number in the ID field when I enter data into my tables.
Does MS SQL have a feature similar to this? I checked all the data types and
the only thing that I see that is close to autonumber is uniqueidentifier. Is
that the same thing?
Walker_Michael wrote:
> I've been using MS Access 2000 for a while and have recently switched
> to MS SQL 2000. When creating a primary key I am used to MS Access
> ability to auto matically enter a number in the ID field when I enter
> data into my tables. Does MS SQL have a feature similar to this? I
> checked all the data types and the only thing that I see that is
> close to autonumber is uniqueidentifier. Is that the same thing?
No, not really. What you want is an IDENTITY column (attached to a
numeric data type) as in:
Create Table Customers (
CustID INT IDENTITY NOT NULL )
Unique identifiers can be used as well, but you need to generate the
number manually using the newid() function. They consists of a 16-byte
hexadecimal number (GUID). Some SQL Server users use them as keys. They
are used frequently in replication. The INT IDENTITY can accommodate
more than 2 Billion values and is only 4-bytes as opposed to 16.
The return the last identity value inserted, you should use
scope_identity(). From a stored procedure, you could use:
Create Proc dbo.UpdateCustomer
@.CustID INT OUTPUT,
@.CustName VARCHAR(50
as
Begin
If @.CustID IS NOT NULL
Update dbo.Customers
Set CustName = @.CustName
Where CustID = @.CustID
Else
Begin
Insert dbo.Customers (
CustName)
Values (
@.CustName )
Set @.CustID = SCOPE_IDENTITY()
End
End
To call this procedure:
Declare @.CustID INT
Exec dbo.UpdateCustomer @.CustID OUTPUT, 'David Gugick'
Select @.CustID
David Gugick
Imceda Software
www.imceda.com
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