Looking for a global key word...

I'm working on a search engine using MySql database and PHP, and would like to allow users not to fill in all fields. I would like to right a generic query that in case a field was not filled in, a key word such as "any" or so would be inserted and would return all entries in the table..Is there such a key word in MySql?

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michael stange

If you can't leave it null, just give a default for the field when you define the table.

Thanks Rod, but thats not exactly what I ment. The user of the search engine might leave a few of the search fields empty, and when I pose the query I would like for those fields to return all entries in the matching table. For example if he wishes to search for a book and only enters the Autors name I want the my one query to fetch all the books that were writen by that Author and because he has the option to also add to the search a year of publication I want, in case it's null to put in a general key word like "any" that will just return all books from any year... Sorry if I wasn't clear with my question.

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michael stange

Ahh, I see.

Well, you could do one of two things. First, if you build your query properly it shouldn't matter if the field is blank:

$query="select * from table_name where author LIKE '%$author%' AND publisher LIKE '%$pub%'";

You see if the field was empty on the form it would send to mysql field LIKE '%%' which should match everything.

Another option is to build the query dynamically (assuming text fields are in an array):

$query="select * from table where";
$add=0;
while (list($key,$value)=each($search_term))
{
if ($value)
{
if (!$add) $query.=" AND";
$add++;
$query.="$key LIKE '%$value%'";
}
}

If you make the array index the same as the column in the table it makes it easier as you can see.

HTH

K Thanks, I'll give it a try.
It sounds like a very good solution...