Mysql update command from csv data - mysql

Question

I am going round in circles, please can someone help with what I guess is a relatively easy problem.
I have a table with 1200 users.
One of the fields in table db_user_accounts is 'status'
I have a sub list of those users in a csv that I want to set the 'status' to '5'
the csv is ordered user, status
I found this -
<?php
if (($handle = fopen("input.csv", "r")) !== FALSE)
{
while (($data = fgetcsv($handle, 1000, ",")) !== FALSE)
{
mysql_query(UPDATE db-user_accounts SET status="{$data[1]}" WHERE user = "{$data[0]}");
}
fclose($handle);
}
?>
Im not sure what the 1000 is for or whether this will actually work.
Any advice gratefully recieved
thanks

Answer 1

This code seems good and should work. 1000 is the length of the line, as from the PHP manual (quoting below):
Ref:http://php.net/manual/en/function.fgetcsv.php
Must be greater than the longest line (in characters) to be found in
the CSV file (allowing for trailing line-end characters). Otherwise,
the line is split into chunks of length characters unless the split
would occur inside an enclosure.
Omitting this parameter (or setting it to 0 in PHP 5.1.0 and later)
the maximum line length is not limited, which is slightly slower.
What your code does is:
Open the CSV file in reading mode, if the file is opened successfully it will enter into the loop
It will then start reading line by line (considering line length up to 1000) till the end of the file. The third parameter , is a delimiter.
The output variable $data will contain the values read from the current line i.e. it will hold user account id and status.
Then you are running MySQL query to update the database.
And finally closes the opened CSV file.
Now, advice:
You are directly passing the values read from CSV file into plain SQL query, doing so may cause unwanted errors, worst SQL injection
What I will suggest is to perform some kind of input validation on the data read from the CSV file and then use parameterized SQL query.
Also, you are using MySQL functions which are deprecated now. Use either Mysqli or PDO.