Hello- yet another question data logging question: I'm working on a program that lets users launch programs and settings on a variety of pcs, switches, etc. I'm logging output from all the processes using trace variable expect_out(buffer). Each process is currently logged to a file named after the host on which the process is being run. I'd like to store the logged output of these console programs (iperf,tcpdump,etc) into mysql in the table below

mysql> describe experiment_results;
+------------+--------------+------+-----+---------+-------+
| Field      | Type         | Null | Key | Default | Extra |
+------------+--------------+------+-----+---------+-------+
| exp_name   | varchar(80)  | YES  |     | NULL    |       |
| seq_number | mediumint(9) | YES  |     | NULL    |       |
| output     | longtext     | YES  |     | NULL    |       |
+------------+--------------+------+-----+---------+-------+
3 rows in set (0.01 sec)

I've tried reading in the files by the technique below,but as you can see, the result is just NULL. I read the docs on using LOAD_FILE and it says that the function will return NULL if  the file is (1) not located on the server, (2) bigger than max_packet_size or (3) not listed via an absolute path. As far as I know I've satisfied all the requirements for this to work. I'm not sure about the max_packet_size issue, but a show variables does not reveal a max_packet_size variable at all. Alternatively, I wouldn't mind writing program output directly to the database, but I'm not sure what sort of buffering I'd have to setup to do that, other than perhaps within Expect/tcl have an array indexed by spawn_id and have the trace lappend output as it comes in to the appropriate cell in the array.

 mysql> update experiment_results set output=LOAD_FILE("/home/thatguy/refactor/test_monitor/n0a0.log");
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from experiment_results;
+----------+------------+--------+
| exp_name | seq_number | output |
+----------+------------+--------+
| exp1     |       NULL | NULL   |
+----------+------------+--------+
1 row in set (0.00 sec)

Long story short, does anyone know of a good way to log large text data into a single field in a mysql table, by any means?

Hmm. I would wonder about loading from file ...

Question noted;   I'm in an internet cafe at the moment; question is a good one; I'll have a play about and post an answer next time I'm around

the approach I took so far was to do the file reading in tcl- read the contents of the file into a variable and then use mysqltcl to insert the contents of that variable into a field, thus obviating the need for mysql's nonstandard load_file. This seems to work fine, but I'm wondering whether it really makes sense to write out the files at all if the final destination is a database. I think using only variables for the temporary storage would be complicated- not sure how the buffering would work.



I've tried out a 250k shell session, and saved it into a database with no problem;  I used PHP, and the "trick" is to use a normal insert command, but add extra \ characters to protect things like " which would  normally be the terminating string.  In PHP the function I used is "quotemeta"; "addslashes" might do it as well.  I don't have Tcl to hand this week, alas  

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