sql concatenation

Question

Can I concatenate queries like below? If no, how should I proceed? I don't want to read rows from $retrieveUnitExist as it waste another step.

$retrieveUnitExist = "SELECT unitid FROM ESTATEUNIT WHERE BLOCK = 1";
$insertAddress = "INSERT INTO ADDRESS (value1, value2) VALUES ('1','".$retrieveUnitExist."')";

mysqli_query($conn, $insertAddress);

Answer 1

Something like this?

$insertAddress = "INSERT INTO ADDRESS (value1, value2)
                  SELECT '1', unitid FROM ESTATEUNIT WHERE BLOCK = 1";