不能加入两个以上的表

Question

I have 3 tables:

table1

fields : id, title, cat1_id

table2

fields : id, title, cat2_id

table3 

fields : id, title

My SQL :

SELECT a.id, a.title, b.title, c.title 
FROM table1 AS a 
INNER JOIN table2 AS b ON b.id = a.cat1_id 
AND INNER JOIN table3 AS c ON c.id = b.cat2_id 
ORDER BY a.id DESC

it's not working.

I try this SQL, it's working:

SELECT a.id, a.title, b.title, c.title 
FROM table1 AS a 
INNER JOIN table2 AS b ON b.id = a.cat1_id 
ORDER BY a.id DESC

but double INNER JOIN does not work.

Answer 1

You do not need to use AND before JOIN to join more that two tables.

Your query should be

SELECT a.id, a.title, b.title, c.title 
FROM table1 AS a 
INNER JOIN table2 AS b ON b.id = a.cat1_id 
INNER JOIN table3 AS c ON c.id = b.cat2_id 
ORDER BY a.id DESC

Have a look at MySQL JOIN Syntax