How to read and write very large files into sqlite - blob columns in PHP?

I want to insert an (arbitrarily large) uploaded file into an sqlite3-database in PHP.

Normally I would use file_get_contents() and then put the string into an SQL-command, but then I run into the 128MB memory limit.

According to this discussion thread, there seems to be also no easy command-line solution. (But of course I would be happy to hear otherwise.)

How can I read/write a single BLOB-field without running out of memory?