<p>A DB Audit Trail captures the User Last Modified, Modified Date, and Created Date.</p>

<p>There are several possible implementations:</p>

<ul>
<li>SQL Server Triggers</li>
<li>Add UserModified, ModifiedDate, CreatedDate columns to the database and include logic in Stored Procedures or Insert, Update statements accordingly.</li>
</ul>

<p>It would be nice if you include implementation (or link to) in your answer.  </p>

[{'answer_id': 60924, 'author': 'Iain Holder', 'author_id': 1122, 'author_profile': 'https://Stackoverflow.com/users/1122', 'pm_score': 4, 'selected': True, 'text': '<p>Depending on what you\'re doing, you might want to move the audit out of the data layer into the data access layer.  It give you more control.</p>\n\n<p>I asked a similar question wrt NHibernate and SqlServer <a href="https://stackoverflow.com/questions/15917/data-auditing-in-nhibernate-and-sqlserver">here</a>.</p>\n'}, {'answer_id': 60982, 'author': 'Alvaro Rodriguez', 'author_id': 1550, 'author_profile': 'https://Stackoverflow.com/users/1550', 'pm_score': 1, 'selected': False, 'text': '<p>I totally second @IainMH (and voted him up).</p>\n\n<p>You want to have it in your DAL and ideally tied to some kind of aspect/interceptor/code injection mechanism.</p>\n'}, {'answer_id': 60989, 'author': 'Aidan Ryan', 'author_id': 1042, 'author_profile': 'https://Stackoverflow.com/users/1042', 'pm_score': 1, 'selected': False, 'text': '<p>+2 for implementation of <strong>when/how</strong> to audit in the DAL.</p>\n\n<p>As for where the audit entries themselves should live, it depends on how it will be visible.  I\'d do a separate table if users can view a separate "audit trail report," but tag existing tables if you want to display last modified-type audits inline.</p>\n'}, {'answer_id': 71965, 'author': 'Chris Burgess', 'author_id': 6624, 'author_profile': 'https://Stackoverflow.com/users/6624', 'pm_score': 0, 'selected': False, 'text': '<p>Here is the implementation I use to audit tables:\n<a href="http://www.simple-talk.com/sql/database-administration/pop-rivetts-sql-server-faq-no.5-pop-on-the-audit-trail/" rel="nofollow noreferrer">Pop Rivett\'s SQL Server FAQ No.5: Pop on the Audit Trail</a></p>\n'}]
['https://Stackoverflow.com/questions/60920', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/2744/']