Daniel Magliola Daniel Magliola - 1 year ago 117
JSON Question

PHP: json_encode vs serialize for storing in a MySQL database?

I'm storing some "unstructured" data (a keyed array) in one field of my table, and i'm currently using serialize() / unserialize() to "convert" back and forth from array to string.

Every now and then, however, I get errors when unserializing the data. I believe these errors happen because of Unicode data in the strings inside the array i'm serializing, although there are some records with Unicode data that work just fine. (DB field is UTF-8)

I'm wondering whether using json_encode instead of serialize will make a difference / make this more resilient. This is not trivial for me to test, since in my dev environment everything works well, but in production, every now and then (about 1% of records) I get an error.

Btw, I know i'm weaseling out of finding an actual explanation for the problem and just blindly trying something, I'm kind of hoping I can get rid of this without spending too much time on it.

Do you think using json_encode instead of serialize will make this more resilient to "serialization errors"? The data format does look more "forgiving" to me...

UPDATE: The actual error i'm getting is:

Notice: unserialize(): Error at offset 401 of 569 bytes in C:\blah.php on line 20


Answer Source

Found this in the PHP docs...

function mb_unserialize($serial_str) { 
    $out = preg_replace('!s:(\d+):"(.*?)";!se', "'s:'.strlen('$2').':\"$2\";'", $serial_str ); 
    return unserialize($out); 

I don't quite understand it, but it worked to unserialize the data that I couldn't unserialize before. Moved to JSON now, i'll report in a couple of weeks whether this solved the problem of randomly getting some records "corrupted"

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