PHP-MySql从具有多个条件的表中选择

Question

I need to select all from database when "main=1" once, then select all from database when "main=0" and use them within the same request . Can I do this in one request? this is the request

1.

$result = $apt->query("SELECT * FROM cat where main='0'");

while($row=$apt->dbarray($result)){

@extract($row);

2.

$result = $apt->query("SELECT * FROM cat where main='1'");

while($row=$apt->dbarray($result)){

@extract($row);

I kind of need to combine them in one request because this will make a conflict when do 2 request. Thanks

Answer 1

You have a couple of options

SELECT * from cat where main = '0' or main ='1'; 

or

SELECT * from cat where main in ('0','1');

If what you meant by a conflict is in reference to maintaining concurrency between the two queries, this way and wrapping the entire operation in a transaction are the only ways to ensure concurrency.

Here is an example of how you can use the queries above to emulate the code you provided but doing it in a single query.

  $result = $apt->query("SELECT * FROM cat where main='0' or main = '1' order by main");
  while($row=$apt->dbarray($result)){
        @extract($row);
        switch ($main){
            case 0:
                // do stuff for when main = 0
                break;
            case 1:
                // do stuff for when main = 1
                break;
        }
  }

Answer 2

1) Create 1 array and insert the result inside that array.

$array = array();
$result = $apt->query("SELECT * cat where main='0'");

while($row=$apt->dbarray($result)){
    $array['main0'][]  = $row[];
}

$result = $apt->query("SELECT * cat where main='1'");

while($row=$apt->dbarray($result)){
    $array['main1'][]  = $row[];
}

echo json_encode($array);

2) OR you can use 1 query with IN

$result = $apt->query("SELECT * cat where main IN ('0','1')");

while($row=$apt->dbarray($result)){
    $array['main0'][]  = $row[];
}