Tag: administration

It happens often that I forget to change the default character set of a database to utf8 and so find out late in the development cycle that many of my fields are based on non utf8 character sets (mostly latin1). Then I go in and modify each field in turn using ALTER TABLE [table] MODIFY [field name] [field type] CHARACTER SET [charset]. After some digging I found the ALTER TABLE $TABLE CONVERT TO CHARSET [charset] syntax which converted all fields in a table to a certain character set. I looked for a similar syntax to convert the entire database and found ALTER DATABASE which, unfortunately, only changes the default character set and collation but does not affect the existing tables, fields or data.

So here is a script that repeats ALTER TABLE / CONVERT TO on each table in your database:

#!/bin/bash
 
# parameters...
USER='[your db user name]'
PASS='[your db password]'
DB='[your db]'
CHARSET='[character set (utf8?)]'
COLLATION='[collation (utf8_unicode_ci?)]'
 
# here we go...
QUERY="SELECT table_name FROM information_schema.TABLES WHERE table_schema = '$DB';"
TABLES=$(mysql -u $USER --password=$PASS $DB --batch --skip-column-names --execute="$QUERY")
for TABLE in $TABLES; do
        echo "ALTER TABLE $TABLE ......"
        mysql -u $USER --password=$PASS $DB -e "ALTER TABLE $TABLE CONVERT TO CHARSET $CHARSET"
        #mysql -u $USER --password=$PASS $DB -e "ALTER TABLE $TABLE CONVERT TO CHARSET $CHARSET COLLATE $COLLATION"
done