Hvorfor virker Select into Outfile kun til nyt filnavn?

Du kan lave et php-script, der sletter den gamle fil ;)

Fra manualen: "The SELECT ... INTO OUTFILE 'file_name' form of SELECT writes the selected rows to a file. The file is created on the server host, so you must have the FILE privilege to use this syntax. file_name cannot be an existing file, which among other things prevents files such as /etc/passwd and database tables from being destroyed."

Men ellers vil jeg normalt overveje at bruge mysqldump eller mysqlhotcopy til backup: http://dev.mysql.com/doc/refman/5.0/en/mysqldump.html

Tak for kommentaren, frygtede, at manualen betød det :-)
Laver et php-script!

Har endda fået denne her til at virke, måske af interesse for nogle; har ikke selv kunnet finde eksempler i den retning på nettet:

SELECT dagbog.* INTO OUTFILE 'C:/Programmer/xampp/mysql/data/dagbog.csv'
  FIELDS TERMINATED BY ';' OPTIONALLY ENCLOSED BY '\"'
  LINES TERMINATED BY '\r\n'
  FROM dagbog, kursister WHERE dagbog.kursistnr = kursister.kursistnr" );