how make multiple statement loops in one? (performance prob/PHP) - php

Question

how do i optimize the following code?
How I can reduce the 4 loops to one, they are almost always the same MySQL statements. Only the step value in the WHERE is always different.
Currently the loading time for this part in the code is about 5-7 sec and that is too long ... each loop make max. 200-300 passes.
// Tank battles heute MySQL
$tday = array();
$result2 = mysqli_query($db, "SELECT * FROM activity_day_account_vehicles WHERE account_id = '$me_id' AND step = '$step'");
while($row_tday = mysqli_fetch_assoc($result2)) {
$t_id = $row_tday['tank_id'];
$tday[$t_id] = $row_tday['statistics_battles'];
}
// Tank battles gestern MySQL
$tday2 = array();
$result3 = mysqli_query($db, "SELECT * FROM activity_day_account_vehicles WHERE account_id = '$me_id' AND step = '$step2'");
while($row_tday2 = mysqli_fetch_assoc($result3)) {
$t_id = $row_tday2['tank_id'];
$tday2[$t_id] = $row_tday2['statistics_battles'];
}
// Tank battles Woche MySQL
$tweek = array();
$result4 = mysqli_query($db, "SELECT * FROM activity_day_account_vehicles WHERE account_id = '$me_id' AND step = '$step3'");
$menge2 = mysqli_num_rows($result4);
if ($menge2 === 0) {
$result4 = mysqli_query($db, "SELECT * FROM activity_day_account_vehicles WHERE account_id = '$me_id' ORDER BY step ASC LIMIT $anzahl2");
}
while($row_tweek = mysqli_fetch_assoc($result4)) {
$t_id = $row_tweek['tank_id'];
$tweek[$t_id] = $row_tweek['statistics_battles'];
}
// Tank battles Monat MySQL
$tmonth = array();
$result5 = mysqli_query($db, "SELECT * FROM activity_day_account_vehicles WHERE account_id = '$me_id' AND step = '$step4'");
$menge2 = mysqli_num_rows($result5);
if ($menge2 === 0) {
$result5 = mysqli_query($db, "SELECT * FROM activity_day_account_vehicles WHERE account_id = '$me_id' ORDER BY step ASC LIMIT $anzahl2");
}
while($row_tmonth = mysqli_fetch_assoc($result5)) {
$t_id = $row_tmonth['tank_id'];
$tmonth[$t_id] = $row_tmonth['statistics_battles'];
}

Answer 1

Create indexes on account_id and step:
CREATE INDEX activity_day_account_vehicles_001
ON activity_day_account_vehicles (account_id);
CREATE INDEX activity_day_account_vehicles_002
ON activity_day_account_vehicles (step);