inner join sql 2 tables code example

Example 1: how to inner join 4 tables in sql

# no need to use parentheses - works fine
SELECT * FROM names A
INNER JOIN address B ON A.personID = B.personID
INNER JOIN emailAddress C ON A.personID = C.personID
INNER JOIN phoneNumbers D ON A.personID = D.personID;

Example 2: two inner joins

SELECT 
  c.*, i.*, a.* 
FROM 
  invoices i 
INNER JOIN 
  client c 
ON 
  i.clientid = c.clientid 
INNER JOIN 
  address a 
ON 
  a.clientid = c.clientid 
WHERE 
  i.id = 21