将来自2个不同源的数据插入MySQL中的一个表中

Question

I'm very new to MySQL and PHP. I have two tables. The first one is users which has the information for the site users and the second table is called SendRequests.

I want to store the data each user posts (it's like an ad posting site) in the second table where I want the first column to be for the email of the logged-in user so I can find the posts from that user later. This is how I am trying to do it:

Using two INSERTs as follows:

$query1=" INSERT INTO SendRequests (email) SELECT email FROM users
WHERE id = '".$_SESSION['id']."' LIMIT 1";

mysqli_query($link, $query1);

$_SESSION['id']= mysqli_insert_id($link);


$query = "INSERT INTO `SendRequests` (`country`, `city`, `fee`) VALUES
('".mysqli_real_escape_string($link,$_POST['departurecountry'])."',
'".mysqli_real_escape_string($link, $_POST['departurecity'])."',
'".mysqli_real_escape_string($link,$_POST['fee'])."')."')
WHERE id = '".$_SESSION['id']."'";

mysqli_query($link, $query);

Answer 1

You can use this query to insert data while searching for your email :

INSERT INTO SendRequests(email, country, city, fee)
SELECT email, "FR", "Paris", 56.65
FROM SendRequests
WHERE id = 1;

This will works if a row with id 1 is already inserted. You can by this way merge your 2 insert in a single one.

So if the SendRequests with id 1 is equal to [e-mail], and you run the query above, you'll have at least 2 rows :

ID EMAIL          COUNTRY  CITY    FEE
========================================
1  [e-mail]  US       Florida 150.25
2  [e-mail]  FR       Paris   56.65