php - with - how to use blob to store an image in a database
How to store.pdf files into MySQL as BLOBs using PHP? (2)
How to store .pdf files into MySQL as BLOBs from PHP?
EDITED TO ADD: The following code is outdated and won't work in PHP 7. See the note towards the bottom of the answer for more details.
Assuming a table structure of an integer ID and a blob DATA column, and assuming MySQL functions are being used to interface with the database, you could probably do something like this:
$result = mysql_query 'INSERT INTO table ( data ) VALUES ( \'' . mysql_real_escape_string (file_get_contents ('/path/to/the/file/to/store.pdf')) . '\' );';
A word of warning though, storing blobs in databases is generally not considered to be the best idea as it can cause table bloat and has a number of other problems associated with it. A better approach would be to move the file somewhere in the filesystem where it can be retrieved, and store the path to the file in the database instead of the file itself.
Also, using mysql_* function calls is discouraged as those methods are effectively deprecated and aren't really built with versions of MySQL newer than 4.x in mind. You should switch to mysqli or PDO instead.
UPDATE: mysql_* functions are deprecated in PHP 5.x and are REMOVED COMPLETELY IN PHP 7! You now have no choice but to switch to a more modern Database Abstraction (MySQLI, PDO). I've decided to leave the original answer above intact for historical reasons but don't actually use it
Here's how to do it with mysqli in procedural mode:
$result = mysqli_query ($db, 'INSERT INTO table ( data ) VALUES ( \'' . mysqli_real_escape_string (file_get_contents ('/path/to/the/file/to/store.pdf'), $db) . '\' );');
The ideal way of doing it is with MySQLI/PDO prepared statements.
In regards to Gordon M's answer above, the 1st and 2nd parameter in
mysqli_real_escape_string () call should be swapped for the newer php versions,
according to: http://php.net/manual/en/mysqli.real-escape-string.php