一次执行多个或三个查询

I'm currently creating an online reservation system.

How can I execute multiple queries at once?

I'm already using mysqli_muti_query. I have three queries to execute.

<?php
$sql = "INSERT INTO db (name,picuploc,lname,pnumber,age,email,address,city,zipcode,ticketid,pickuptime,dropofftime,dropoffloc,vehicle,plateno,totalprice,date_registered) VALUES ('$first','$pickuploc','$lname','$pnumber','$age','$email','$address','$city','$zip','$ticket','$pickup','$dropoff','$dropoffloc','$car','$plate','$all', NOW());";

$sql .= "UPDATE vehicles set quantity = quantity - $age WHERE vehicle = '$car' AND parent = '$ye' ";

$sql .= "UPDATE vehicles set status = '$un'  WHERE plateno = '$plate' "; ?>

You need to Add semicolon after each statement:

<?php
$sql = "INSERT INTO db (name,picuploc,lname,pnumber,age,email,address,city,zipcode,ticketid,pickuptime,dropofftime,dropoffloc,vehicle,plateno,totalprice,date_registered) VALUES ('$first','$pickuploc','$lname','$pnumber','$age','$email','$address','$city','$zip','$ticket','$pickup','$dropoff','$dropoffloc','$car','$plate','$all', NOW());";

$sql .= "UPDATE vehicles set quantity = quantity - $age WHERE vehicle = '$car' AND parent = '$ye' ;";

$sql .= "UPDATE vehicles set status = '$un'  WHERE plateno = '$plate' ;"; 

If supported by your database, I'd suggest that you run your queries separately and wrap them into a single transaction.

$conn->begin_transaction();
$sql = "INSERT INTO db (name,picuploc,lname,pnumber,age,email,address,city,zipcode,ticketid,pickuptime,dropofftime,dropoffloc,vehicle,plateno,totalprice,date_registered) VALUES ('$first','$pickuploc','$lname','$pnumber','$age','$email','$address','$city','$zip','$ticket','$pickup','$dropoff','$dropoffloc','$car','$plate','$all', NOW());";
$conn->query($sql);

$sql = "UPDATE vehicles set quantity = quantity - $age WHERE vehicle = '$car' AND parent = '$ye';";
$conn->query($sql);

$sql = "UPDATE vehicles set status = '$un'  WHERE plateno = '$plate';";
$conn->query($sql);

$conn->commit();

I'd also suggest that you use prepared statements with parameters rather than including values directly into your query string.

You can use PHP mysqli_multi_query-function.

$sql = "INSERT INTO db (name,picuploc,lname,pnumber,age,email,address,city,zipcode,ticketid,pickuptime,dropofftime,dropoffloc,vehicle,plateno,totalprice,date_registered) VALUES ('$first','$pickuploc','$lname','$pnumber','$age','$email','$address','$city','$zip','$ticket','$pickup','$dropoff','$dropoffloc','$car','$plate','$all', NOW());";

$sql .= "UPDATE vehicles set quantity = quantity - $age WHERE vehicle = '$car' AND parent = '$ye' ;";

$sql .= "UPDATE vehicles set status = '$un'  WHERE plateno = '$plate' ;"; 

/* execute multi query */
if ($mysqli->multi_query($query)) {

}