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Timestamping an existing table [Table of Contents] Join cursor processing and data modifications

Transact-SQL User's Guide

[-] Chapter 17 Cursors: Accessing Data Row by Row
[-] Using browse mode instead of cursors
[-] Comparing timestamp values

Comparing timestamp values

Use the tsequal system function to compare timestamps when you are using browse mode in a front-end application. For example, the following statement updates a row in publishers that has been browsed. It compares the timestamp column in the browsed version of the row with the hexadecimal timestamp in the stored version. If the two timestamps are not equal, you receive an error message, and the row is not updated.

update publishers
set city = "Springfield"
where pub_id = "0736"
and tsequal(timestamp,0x0001000000002ea8)

Do not use the tsequal function in the where clause as a search argument. When you use tsequal, the rest of the where clause should match a single row uniquely. Use the tsequal function only in insert and update statements. If a timestamp column is used as a search clause, it should be compared like a regular varbinary column, that is, timestamp1 = timepstamp2.

Timestamping an existing table [Table of Contents] Join cursor processing and data modifications