Getting encoding right is really tricky - there are too many layers:
The SQL command "SET CHARSET utf8" from PHP will ensure that the client side (PHP) will get the data in utf8, no matter how they are stored in the database. Of course, they need to be stored correctly first.
DDL definition vs. real data
Encoding defined for a table/column doesn't really mean that the data are in that encoding. If you happened to have a table defined as utf8
but stored as differtent encoding, then MySQL will treat them as utf8
and you're in trouble. Which means you have to fix this first.
What to check
You need to check in what encoding the data flow at each layer.
- Check HTTP headers, headers.
- Check what's really sent in body of the request.
- Don't forget that MySQL has encoding almost everywhere:
- Database
- Tables
- Columns
- Server as a whole
- Client
Make sure that there's the right one everywhere.
Conversion
If you receive data in e.g. windows-1250
, and want to store in utf-8
, then use this SQL before storing:
SET NAMES 'cp1250';
If you have data in DB as windows-1250
and want to retreive utf8
, use:
SET CHARSET 'utf8';
Last note:
Don't rely on too "smart" tools to show the data. E.g. phpMyAdmin does (was doing when I was using it) encoding really bad. And it goes through all the layers so it's hard to find out. Also, Internet Explorer had really stupid behavior of "guessing" the encoding based on weird rules. Use simple editors where you can switch encoding. Also, I recommend MySQL Workbench.