title: How can i insert only into one column without getting null to others
body: <p>I need to insert into a data-base column without overwriting values for other columns.. Heres my php code where I check every column if it has to be overwritten with "si" or no value at all.. The thing is only last column gets the value "si" and all of others a value of "null".. HOw can i insert only into one column without getting null or '' to the others!</p>
  
  <pre><code>if($canSend){
  
              $queryUser="CREATE TABLE `$email` ( lun8semanauno VARCHAR(30), 
                              lun10semanauno VARCHAR(30), lun16semanauno VARCHAR(30),lun18semanauno VARCHAR(30), lun20semanauno VARCHAR(30));";
              $queryu=mysql_query($queryUser,$db); 
   }
  
  //Ahora sumo uno al cupo si es que esta todo bien de arriba:    
      if($canSend &amp;&amp; $horarios == "Lunes 8:30hs-Clase grupal"){
              $nuevocupolun8=$info['cuposLun8']+1;
              $queryRestar="UPDATE  `cupos` SET  `cuposLun8`='$nuevocupolun8'   WHERE  `cupos`.`cuposLun8` =  '$cupolun8';";
              $restar=mysql_query($queryRestar,$db);
  
              $queryAdd="INSERT INTO `lahiguera_hor`.`$email` (`lun8semanauno`) VALUES ('si');";
              $querya=mysql_query($queryAdd,$db);
          }
      if($canSend &amp;&amp; $horarios == "Lunes 10hs-Meditacion"){
              $nuevocupolun10=$info['cuposLun10']+1;
              $queryRestar="UPDATE  `cupos` SET  `cuposLun10`='$nuevocupolun10'   WHERE  `cupos`.`cuposLun10` =  '$cupolun10';";
              $restar=mysql_query($queryRestar,$db);
  
              $queryAdd="$queryAdd="INSERT INTO `lahiguera_hor`.`$email` (`lun10semanauno`) VALUES ('si');";
              $querya=mysql_query($queryAdd,$db);
          }
      if($canSend &amp;&amp; $horarios == "Lunes 16hs-Futuras mamas"){
              $nuevocupolun16=$info['cuposLun16']+1;
              $queryRestar="UPDATE  `cupos` SET  `cuposLun16`='$nuevocupolun16'   WHERE  `cupos`.`cuposLun16` =  '$cupolun16';";
              $restar=mysql_query($queryRestar,$db);
  
              $queryAdd="INSERT INTO `lahiguera_hor`.`$email` (`lun16semanauno`) VALUES ('si');";
              $querya=mysql_query($queryAdd,$db);
          }       
      if($canSend &amp;&amp; $horarios == "Lunes 18hs-Clase grupal"){
              $nuevocupolun18=$info['cuposLun18']+1;
              $queryRestar="UPDATE  `cupos` SET  `cuposLun18`='$nuevocupolun18'   WHERE  `cupos`.`cuposLun18` =  '$cupolun18';";
              $restar=mysql_query($queryRestar,$db);
  
              $queryAdd="INSERT INTO `lahiguera_hor`.`$email` (`lun18semanauno`) VALUES ('si');";
              $querya=mysql_query($queryAdd,$db);
          }           
      if($canSend &amp;&amp; $horarios == "Lunes 20hs-clase grupal"){
              $nuevocupolun18=$info['cuposLun20']+1;
              $queryRestar="UPDATE  `cupos` SET  `cuposLun20`='$nuevocupolun20'   WHERE  `cupos`.`cuposLun20` =  '$cupolun20';";
              $restar=mysql_query($queryRestar,$db);
  
              $queryAdd="INSERT INTO `lahiguera_hor`.`$email` (`lun20semanauno`) VALUES ('si');";
              $querya=mysql_query($queryAdd,$db);
          }
  </code></pre>