Question

I have a query string being built and it works fine when I use LIKE but it will not work with NOT LIKE

 $sWhere = "";
    if ( $_GET['sSearch'] != "" )
    {

            $aWords = preg_split('/\s+/', $_GET['sSearch']);
            $sWhere = "WHERE (";

            for ( $j=0 ; $j<count($aWords) ; $j++ )
            {
                    if ( $aWords[$j] != "" )
                    {
                            if(substr($aWords[$j], 0, 1) == "!"){
                                    $notString = substr($aWords[$j], 1);
                                    $sWhere .= "(";
                                    for ( $i=0 ; $i<count($aColumns) ; $i++ )
                                    {
                                            $sWhere .= $aColumns[$i]." NOT LIKE '%".mysql_real_escape_string( $notString )."%' OR ";
                                    }
                            }
                            else{
                                    $sWhere .= "(";
                                    for ( $i=0 ; $i<count($aColumns) ; $i++ )
                                    {
                                            $sWhere .= $aColumns[$i]." LIKE '%".mysql_real_escape_string( $aWords[$j] )."%' OR ";
                                    }
                            }
                            $sWhere = substr_replace( $sWhere, "", -3 );
                            $sWhere .= ") AND ";
                    }
            }
            $sWhere = substr_replace( $sWhere, "", -4 );

the part of the code that does work is:

 if(substr($aWords[$j], 0, 1) == "!"){
                                    $notString = substr($aWords[$j], 1);
                                    $sWhere .= "(";
                                    for ( $i=0 ; $i<count($aColumns) ; $i++ )
                                    {
                                            $sWhere .= $aColumns[$i]." NOT LIKE '%".mysql_real_escape_string( $notString )."%' OR ";
                                    }
                            }

if I remove the “NOT” the query works fine but it does nothing when I add the NOT.

thanks

Answer 1

It’s because you are using OR in your NOT LIKE condition.

Finding all the rows where column1 NOT LIKE “a” OR column2 NOT LIKE “a” will match everything.