Joining Tables

Radon3k

If I have a table, "names", that has an ID field (INT, PRIMARY KEY, AUTO_INCREMENT) and some other fields that are irrelevant, and another table, "locations" that also has an ID field but I want to make them have the same ID number, how would I do this? I know it's called joining but I'm not quite sure how the process works. It's like on a message board when you reply to a topic, in the post there is the topic ID, but the topic itself has an ID that is the same thing. Could someone please explain how this works and maybe give an example? Thanks! 🙂

leatherback

Hi,

I am not completely sure if this is what you are looking for, but eh.. Assuming you just want to be able to refer to entries in one table, using an id from an other table:

Each table has a unique identifier, ID, which are not the same, but just make sure you can identify a specific record in each table. <Yeahyeah, you want the same, we'll get there soon>

Then in locations, you add a field, called nameID. Here you store the ID from table persons.

So, you get the id from persons: Select id as personID from persons where <some criterium>.
Then you insert the data into location:
Insert into location (nameID, location) values ($personID, $locatoin)

Hope it helps,

Radon3k

Hi,

here is my code. I got an error already because of the mysql_fetch_array.

<?php 
// DB conncection info is above. $sql = mysql_query("SELECT ID FROM family");
if($row = mysql_fetch_array($sql)) {
	$famid = $row['ID'];
}

if($_POST['submit'] == "Submit") {
	$insert = mysql_query("INSERT INTO courses SET
				famid = $famid;
				coursename = '$coursename'");

			if($insert) {
				echo("Course added.");
			} else {
				echo("Error adding course name.");
			}
}
?>

That didn' work too well. Any suggestions? Thanks. 🙂

Radon3k

Would anybody know how to do this?

leatherback

I am not sure about the if statement you use.

Try:

while($_POST['submit'] == "Submit")

instead.

Let us know if that doesn't solve it.