Duplicate Data from two column i have a table which has only two column one is pid(Photo ID) and another one is tid(Tag ID)

+-------+---------+------+-----+---------+-------+
| Field | Type    | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| pid   | int(10) | NO   |     | NULL    |       |
| tid   | int(10) | NO   |     | NULL    |       |
+-------+---------+------+-----+---------+-------+


this table will store a photo id with a tag id, but i am facing a problem and i guess which is against normalization as well, here is my table data.

+-----+-----+
| pid | tid |
+-----+-----+
|  10 |   1 |
|  10 |   2 |
|  10 |   3 |
|  10 |   4 |
|   0 |   6 |
|   0 |  10 |
|   0 |  10 |
|  10 |   1 |
|  10 |   2 |
|  10 |   3 |
|  10 |   4 |
+-----+-----+


it store many duplicate values, how to get rid of this?I mean, how i can store this types of row only for one time: |  10 |   1 | 
I have tried with UNIQE but this will going to store a photo id or a tag id only for one time?I'm using PHP
Thanks
You need a compound unique index.

Suppose your table is called photos. You can do this:

CREATE TABLE photos_new LIKE photos;
ALTER TABLE photos_new ADD UNIQUE INDEX pid_tid_index (pid,tid);
INSERT IGNORE INTO photos_new SELECT * FROM photos;
ALTER TABLE photos RENAME photos_old;
ALTER TABLE photos_new RENAME photos;


If it works out, then run

DROP TABLE photos_old;


Give it a Try !!!