Generating Reference Numbers With Sequences

Kevin Feasel

2019-02-25

T-SQL

Matthew McGiffen shares one technique to generate reference numbers using a sequence and the FORMAT function:

One thing to note is that, while the sequence will generally produce unique number, it is still worth enforcing that in your table definition with a unique constraint i.e.

ALTER TABLE dbo.Orders ADD CONSTRAINT UQ_Orders_OrderReference UNIQUE(OrderReference);

This prevents someone from issuing an UPDATE command that might create a duplicate reference. 

As long as you can live with the occasional gap in your reference number, sequences are a good solution to the problem.

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