please help me to know if there is a data in my database table, if there is an existing data therefore i cannot save / insert my current data but if the table is empty or has no duplicate with my current data then i will save to it

in order to best understand your database, begin by thoroughly studying these few items:
MySQL (assuming this is your Database):
http://dev.mysql.com/doc/refman/5.0/...le-status.html

PHP Info about MySQL
http://www.php.net/manual/en/faq.databases.php
http://www.php.net/manual/en/functio...-field-len.php
(from the above, view the list at the left)

EDIT: -- several international localized languages are provided for each manual:
http://dev.mysql.com/doc/
http://www.php.net/docs.php
http://www.php.net/manual/en/about.prototypes.php


I hope that helps!
;)

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Do the hokey pokey.
Turn yourself around.

The single easiest way to prevent duplicate data is to create a unique index on the column that you don't wish to duplicate data in. Whenever an insert occurs which includes data in the column with a unique key assigned, and the data is determined to be duplicate, the insert will fail.