Question

Is it possible to have a char primary key on a table? For example ‘WC001’ then will it automatically increment by 1, so the next record for the pk will be ‘WC002’ and so on.

Can anyone provide me example?

Thanks

Answer 1

Not directly – but you could have a normal INT IDENTITY auto-incrementing numerical ID and then defines a computed persisted column (SQL Server 2005 and newer) – something like:

CREATE TABLE dbo.YourTable
(ID INT IDENTITY(1,1),
 CharID AS 'WC' + RIGHT('000' + CAST(ID AS VARCHAR(3)), 3) PERSISTED,

 CONSTRAINT PK_YourTable PRIMARY KEY(CharID)
)

Inserting values into this table will cause the ID column to be 1, 2, 3, 4, 5, ….. and the CharID column will automatically be WC001, WC002, WC003 and so forth.

Since it’s a persisted computed column, the values is always up to date, and you can even put an index (like the primary key) on it.