DIRP="location of backups"
DATE=$(date +"%m-%d-%y")
MYSQL_SERVER="location of mysql server"
USER="mysql user"
PASSWORD="mysql password
LOOP_VAR="mysql db names without prefix"

for LOOP_VAR_TXT in $LOOP_VAR
  do
    LOOP_VAR_FILE=${DIRP}/${LOOP_VAR_TXT}.${DATE}.sql
    LOOP_VAR_DB="db prefix"_$LOOP_VAR_TXT
    /usr/bin/mysqldump --user=$USER --password=$PASSWORD --host=$MYSQL_SERVER $LOOP_VAR_DB > $LOOP_VAR_FILE
    /usr/bin/tar -czvf ${LOOP_VAR_FILE}.tgz $LOOP_VAR_FILE
    rm $LOOP_VAR_FILE
  done

find ${DIRP}mysql -mtime +13 -exec rm -f {} \;

some quick and dirty code i needed for a quick script