MySQL select into outfile /tmp no output

The files generate by the outfile clause are created on the mysql server host. Please make sure you are looking on the mysql server host as it seems you are on the client host which most likely isn't the mysql server host.

See http://dev.mysql.com/doc/refman/5.0/en/select.html in the section about outfile for documentation regarding this.

I came across this problem in Fedora 17 and it was caused by systemd. I think it's good to share.

mysql> select * into outfile '/tmp/z1' from t1;Query OK, 673 rows affected (0.01 sec)mysql> select * into outfile '/tmp/z2' from t1;Query OK, 673 rows affected (0.01 sec)mysql> select * into outfile '/tmp/z1' from t1;ERROR 1086 (HY000): File '/tmp/z1' already existsmysql> Bye# cat /tmp/z1cat: /tmp/z1: No such file or directory# ls -d systemd-*/tmp/systemd-private-AQEueG/tmp/systemd-private-AuCNDY/tmp/systemd-private-TOMNxZ/tmp/systemd-private-UacrpE/tmp/systemd-private-yal7lQ/tmp/systemd-private-ZlRJeN# ls /tmp/systemd-private-TOMNxZz1  z2

The culprit was in /usr/lib/systemd/system/mysqld.service.

# Place temp files in a secure directory, not /tmpPrivateTmp=true

Thanks to this blog, I found the clue.

Sounds like you might be running into a file permissions problem. Be sure that the user:group that mysqld is running under has adaqute permission to write to /tmp/test.csv

There's a whole variety of server daemon/file permission flavours that would solve the problem. Presumably UNIX-based, you could: chgrp mysqldGROUP /tmp

But that makes it seem so easy- your server is configured in a certain way, so you adapt to that. The mysqld process should really only be able to read/write from a handful of places.