Question

This might be something very simple to do. If so, I apologize. I’m still learning MySQL.

Say, I have two tables:

Table1:
`id` int autoincrement primary key
`Name` tinytext
`Phone` tinytext
`Date` etc.

and

Table2:
`id` int autoincrement primary key
`itmID` int

Each row in Table2 specifes the order at which elements should be selected out of Table1. itmID field in Table2 is linked to id field in Table1.

So right at this moment to select elements from Table1 I do this:

SELECT * FROM `Table1`;

But how do you order them according to Table2, something like this?

SELECT * FROM `Table1` ORDER BY <itmID's in Table2> ASC;

Answer 1

If all ids of the Table1 have an entry on Table2 use an INNER JOIN, like this.

SELECT * FROM Table1 t1
INNER JOIN Table2 t2 ON t1.id = t2.itmID
ORDER BY t2.itmID

If not all of them have an entry, then use a LEFT JOIN, like this:

SELECT * FROM Table1 t1
LEFT JOIN Table2 t2 ON t1.id = t2.itmID
ORDER BY t2.itmID