php - json_encode(): Invalid UTF-8 sequence in argument

Question

I'm calling json_encode() on data that comes from a MySQL database with utf8_general_ci collation. The problem is that some rows have weird data which I can't clean. For example symbol ?, so once it reaches json_encode(), it fails with json_encode(): Invalid UTF-8 sequence in argument.

I've tried utf8_encode() and utf8_decode(), even with mb_check_encoding() but it keeps getting through and causing havoc.

Running PHP 5.3.10 on Mac. So the question is - how can I clean up invalid utf8 symbols, keeping the rest of data, so that json_encoding() would work?

Update. Here is a way to reproduce it:

echo json_encode(pack("H*" ,'c32e'));

Answer 1

I had a similar error which caused json_encode to return a null field whenever there was a hi-ascii character such as a curly apostrophe in a string, due to the wrong character set being returned in the query.

The solution was to make sure it comes as utf8 by adding:

mysql_set_charset('utf8');

after the mysql connect statement.