How to know the updated table in Database ?

One way is write a trigger for every table in which you want to track the changes. And also create another table that has such a structure that can store all of your changed data.

For information about triggers :
http://www.go4expert.com/forums/showthread.php?t=15510[^]

http://msdn.microsoft.com/en-us/magazine/cc164047.aspx[^]

Another way is enabling Change Tracking in your database. to learn more about it read here :
http://www.databasejournal.com/features/mssql/article.php/3875186/A-Look-at-SQL-Server-2008-Change-Tracking.htm[^]

To have a comparison between these two methods read here :
http://msdn.microsoft.com/en-us/library/cc280519%28v=SQL.100%29.aspx[^]

Hope it helps.

Depends on how you define "updated". Updated since when?

I would handle it by adding a DateTime column to the database which reflects the last change. I could then retrieve only the updated records for whatever range I needed with a simple SQL SELECT query.

How about creating a Transaction Log by creating a new table, or saving it as XML or maybe a textfile or a CSV file. So you can use this Transaction Log for your Audit Trailing.

Another solution would be creating a Time Stamp or a Date Updated field o each of your table and updating that field everytime a user updates a record from that table.

Regards,
Eduard

say $name is the value of the updated column, the column name is name, and the table name is testtb, you would type:

$query = mysql_query("SELECT * FROM testdb WHERE name=$name");
$array = mysql_fetch_array($query);
$rnd = $array['<Name of column you want to pull value from>'];
echo "$rnd";