Question : How to merge/copy feilds from one table into another

Hi

I'm trying to patch a table with info from another. Currently I have two tables one user table with there details, and another invoices table,

currently the invoices table entries has a ref to the id of the user but we are changing our system to store the users name with each invoice as the user can change there name at any point and we need it be be static at the point of invoice creation.

So I need to execute a query or set of queries that will get the user.name and place it into a new field in the invoice.user_name table for every entry In the invoice table.
Separately or at the same time I need to add another value thats the same to to all the entries in the invoice table.

Sorry if you now totally confused i'm a little any help would be greatly appreciated.

Thanks
Gaz

Answer : How to merge/copy feilds from one table into another

As far as I can tell you need a two stage soultion. First of all you need to update all your existing invoices to have a username, and secondly you need to modify your invoice creation code to include a username.

Since you are on LAMP, I would probably write a quick php script to update all you old records. This will be very simple, it will simple loop though all your users, and update the invoice table accordingly. See Code example 1.

Secondly, when you create an invoice you probably have a query simular to the following...

$query = "INSERT INTO invoices (user_id, data1) VALUES (".$user_id.", 'somedata')";

See Code sample two which includes a subselect to add the username.

                       
         
           
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             /**
* Code Sample 1 - Update all existing invoices to have usernames
**/
// Get a list of users
$query = "SELECT id, name FROM user ORDER BY id asc";
$result = mysql_query($query);
 
// Loop through the users
while ($row = mysql_fetch_assoc($result))
{
// Update any invoices for this user to include the name
 $update = "UPDATE invoice SET user_name = ".$row['name']." WHERE user_id = ".$row['id'].";
 mysql_query($update);
}
 
/**
* Code Sample 2 
**/
 
// An ID of the user who owns the invoices
$user_id = 1001;
// Some invoice data (specific to your system)
$somedata = "3 Pairs of Shoes";
 
$query = "INSERT INTO invoices (user_id, user_name, data1) VALUES (".$user_id.", 
(SELECT name FROM users WHERE id = ".$user_id.")
'".$somedata."')"; 

           
         

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