Using INSERT WHERE with variables - php

Question

I am trying to make an SQL query that :
IF the $post_id exists then it updates the records,
IF NOT then then it creates the record
Here is my code
$vote_new_total = $vote_total + $vote;
$vote_count = $vote_count + 1;
$query = " INSERT INTO cute_review_vote (vote_total, vote_count)
VALUES ('$vote_new_total', '$vote_count')
ON DUPLICATE KEY UPDATE vote_total = $vote_new_total, vote_count = $vote_count
WHERE post_id = $post_id";
mysql_query($query) or trigger_error(mysql_error()." in ".$sql);
However, I keep getting the following error:
Notice: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE post_id = 214748364' at line 4 in in C:\xampp\htdocs\xbm-vote\do_vote.php on line 68
Is this an issue with my syntax or am I missing something more obvious than that?
Any help/advice would be greatly appreciated. Thanks.

Answer 1

There is no where with ON DUPLICATE statement. Always check syntax: http://dev.mysql.com/doc/refman/5.6/en/insert-on-duplicate.html
Also, that is not a secure query. Turn that into a prepared statement.
http://www.php.net/manual/en/mysqli.quickstart.prepared-statements.php
EDIT: Updating answer since OP didn't understand usage of ON DUPLICATE statement:
ON DUPLICATE will consider that you're trying to insert a KEY value.
Consider the example table:
CREATE TABLE `user` (
`email` varchar(50) NOT NULL,
`name` varchar(20) NOT NULL,
`is_active` tinyint(4) NOT NULL,
`datecreated` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`email`)
);
And the query:
INSERT INTO user (email, name, is_active) VALUES ("user#user.com", "User", 1)
ON DUPLICATE KEY UPDATE name = "User Edited", is_active = 0
Since we're setting PRIMARY KEY as email, and the insert statement is inserting a key, then, at the second time you run the query, ON DUPLICATE would run once a email is already on the table, because it is the KEY and you are trying to insert it again, but you defined a ON DUPLICATE KEY ....
If a table runs with a AUTO_INCREMENT column, is most likely you have to SELECT post_id applying some filter with WHERE statement.

Answer 2

Ok, I found my problem.
INSERT INTO cute_review_vote (post_id, vote_total, vote_count)
VALUES ('$post_id', '$vote_new_total', '$vote_count')
ON DUPLICATE KEY UPDATE vote_total = $vote_new_total, vote_count = $vote_count
I realized, thanks to Fabiano, that the WHERE clause is not required.
WHERE post_id = $post_id"
Is simply replaced by defining the database entry within the INSERT INTO command.