Search Engine

[Dysan]

How do I create a search engine, that searches a database for a specific criteria?

[wilku]

You start by specifiying your criteria. Then you construct SQL statement that pulls out records that satisfy the criteria. If there are many criteria, then you're trying to construct the select statement so that if the specific criteria is not used, it's ommited in the statement.
Very sketchy example

$sql = 'SELECT whatever FROM wherever WHERE 1=1';

if (!empty($phrase)) $sql.=" AND field LIKE '%$phrase%'";
if ($checked) $sql.=" AND field2=1";
//and so on

[/code]

[kakki]

BEWARE:

$sql = 'SELECT whatever FROM wherever WHERE 1=1'; 

i did that once with a DELETE-statement which got its where arguments by
request-parameters
like this:

$sql = 'DELETE FROM wherever WHERE 1=1'; 
if ( isset ( $_REQUEST[ 'fid' ] )
{
       $sql .= " AND fid='".$_REQUEST[ 'fid' ]."';
       execute_sql( $sql );
}
if ( isset ( $_REQUEST[ 'aid' ] )
{
       $sql .= " AND fid='".$_REQUEST[ 'aid' ]."';
       execute_sql( $sql );
}
if ( isset ( $_REQUEST[ 'bid' ] )
{
       $sql .= " AND fid='".$_REQUEST[ 'bid' ]."';
       execute_sql( $sql );
}

got the admins running with tapes 3 times that day 🙂
( the parameter was named "fuid" )

maybe thomething like this:

$sql = array();
if ( isset ( $_REQUEST[ 'fid' ] )
{
       $sql[] = "fid='".$_REQUEST[ 'fid' ]."';
}


$statement = implode( ' AND ', $sql );
if ( is_ok( $statement ) )
{
     execute_sql( 'SELECT whatever FROM wherever WHERE '. $statement );
}

with that you can spare the WHERE 1=1

[wilku]

Well, yeah, I wouldn't use it with delete 😃, but showing everything isn't the same as deleting everything. 😉

[kakki]

at least if you try that code above it would create a statement like this:
"DELETE FROM wherever WHERE"
which would result in an error