Compute hash-value of entered value when insert or update using sql server 2008 by triggers

Question

Hi, i have a table with two column {FlatContent, HashedContent}. Now i want to automatically compute hash value of FlatContent when new row was inserted or an existing row was updated. To date, i'm never used from trigger, so i can't do this by trigger or another approach which is exist to solve this issue.

Thanks if anybody can help me ;)

Answer 1

Instead of using a trigger, make HashedContent a persisted computed column in your table definition.

ALTER TABLE YourTable
    ADD HashedContent AS HashBytes('SHA1', FlatContent) PERSISTED