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Old 05-04-2004, 06:12 AM   #1
philipz
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MySQL queries from Shell - unexpected result


List,

I have a problem with querying a MySQL database from Shell in batch mode.

I have a file called 'mylist' in this format:
10.156.40.36
10.150.133.33
10.140.159.89


Now with a script I make a Class C of every IP address and put that in a tempfile:
use sitedb
SELECT C FROM sitelist WHERE A LIKE "10.156.40.0";
SELECT C FROM sitelist WHERE A LIKE "10.150.133.0";
SELECT C FROM sitelist WHERE A LIKE "10.140.159.0";

Then I merge the output with the following command:
mysql --silent -h 10.10.10.10 -u username -ppassword < tempfile | paste mylist -

This works extremely well and gives this output:
10.156.40.36 Rome
10.150.133.33 Brussels
10.140.159.89 Amsterdam

However, if for instance 10.156.40.0 (Rome) is not found in the database, I don't get a result for that query (luckily). But my output gets shifted and doesn't match anymore:

10.156.40.36 Brussels
10.150.133.33 Amsterdam
10.140.159.89

In my opinion there are 2 options:
Force MySQL to return 'nill' or something similar if the result of a query is nill (no clue how to do that)

Adapt the script one or the other way so that it checks for a result after each query. Also no clue how to do that

Any suggestion would be greatly appreciated...

Kind regards,

Phil
 
Old 05-04-2004, 09:47 AM   #2
crabboy
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You can try something like this:
Code:
SELECT '10.156.40.36', C FROM sitelist WHERE A LIKE "10.156.40.0";
SELECT '10.150.133.33', C FROM sitelist WHERE A LIKE "10.150.133.0";
SELECT '10.140.159.89', C FROM sitelist WHERE A LIKE "10.140.159.0";
 
Old 05-04-2004, 10:34 AM   #3
philipz
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Hmmm, I think I miss something here...
If its an unknow ip-address, it still gives nothing as result, while with a known address it gives 2 results?
 
Old 05-04-2004, 03:54 PM   #4
jim mcnamara
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Try using the IFNULL function -

like
Code:
SELECT  IFNULL( C,'Not found.')  FROM sitelist WHERE A LIKE "10.156.40.0";
Edit : oops used the Oracle syntax.

Last edited by jim mcnamara; 05-04-2004 at 03:58 PM.
 
Old 05-04-2004, 04:52 PM   #5
philipz
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This works if A (10.156.40.0) exists and C is empty (NULL), but NOT if A doesn't exist...
I want 'not found' if A doesn't exist. Is there a similar syntax that does this?

Thx (we're getting close)

- Phil
 
Old 05-04-2004, 05:38 PM   #6
philipz
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Just to clarify, in 'pseudo-code', this would look like:
SELECT C FROM sitelist WHERE IFNOTFOUND( A,'unknown') LIKE "10.156.40.0";
 
  


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