Should be simple? MySQL query: substitute ID (int) in one table with title (varchar) from other table

I have a question which seems very basic to me, but cannot find the answer to it. I have two tables: A & B. Table A has a column with id-s (int), table B connects those id-s with descriptions (varchar.) I want to do a query on table A, where I replace the id-s with the descriptions from table B (one-one relation). I currently have this query:

select tableA.* from tableA join tableB on (tableA.id=tableB.description);

This should do the job, apart from that I get Warning 1292 : "Truncated incorrect DOUBLE value".

I understand what it means, the two data types don't match. But then how to make it work? I am sure this must be a simple fix and that what I ask for is being used all the time (e.g. replace ISBN with book title, etc.)...

Any help would be much appreciated!

Edit upon request

Sorry people, I thought it was not ambiguous... Db structure:

mysql> describe tasks;
+----------+-----------------------+------+-----+---------+----------------+
| Field    | Type                  | Null | Key | Default | Extra          |
+----------+-----------------------+------+-----+---------+----------------+
| tid      | int(10) unsigned      | NO   | PRI | NULL    | auto_increment |
| pid      | int(10) unsigned      | YES  |     | NULL    |                |
| username | varchar(15)           | YES  |     | NULL    |                |
| task     | varchar(1000)         | NO   |     | NULL    |                |
+----------+-----------------------+------+-----+---------+----------------+
8 rows in set (0.00 sec)

mysql> describe projects;
+-------+------------------+------+-----+---------+----------------+
| Field | Type             | Null | Key | Default | Extra          |
+-------+------------------+------+-----+---------+----------------+
| pid   | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| title | varchar(200)     | YES  |     | NULL    |                |
+-------+------------------+------+-----+---------+----------------+
2 rows in set (0.00 sec)

I want to "select * from tasks", where every pid is replaced with the corresponding title from table projects in the same query.

Hope it's now clearer...

Solution

You can simply use the following query to join the contents of both tables getting all entries from the task table even if they have no project attached:

SELECT t.tid, t.username, t.task, p.title 
FROM tasks t 
LEFT JOIN projects p ON t.pid = p.pid;

If you just want tasks with an attached project use this query instead:

SELECT t.tid, t.username, t.task, p.title 
FROM tasks t 
JOIN projects p ON t.pid = p.pid;