I Only Know 2 Tables in Left Join SQL Query. What if I have 3 or More Tables?

Question

I'm creating sql command where the date stored in different table with foreign key of borrowers_id. I can execute and output left join of 2 tables but what if I have 3 or more tables fetching the datas of my foreign key.

Here's my SQL command,

SELECT borrowers.firstname,
borrowers.middlename,
borrowers.lastname,
borrowers.home_address,
borrowers.date_of_birth,
borrowers.age,
borrowers.residential_status,
borrowers.status,
borrowers.date_added,
borrowersp.spouse_name,
borrowersp.date_of_birth,
borrowersp.age 
FROM tblborrowers as borrowers LEFT JOIN tblborrowerspouse as borrowersp 
ON borrowers.borrowers_id = borrowersp.borrowers_id 
WHERE borrowers.borrowers_id=23432413;

You do join them same way likewise you have done. – Rahul Aug 06 '15 at 02:41 — Rahul, Aug 06 '15 at 02:41

score 1 · Accepted Answer · answered Aug 06 '15 at 02:43

You can add more tables by continuing to join:

FROM tblborrowers as borrowers LEFT JOIN tblborrowerspouse as borrowersp 
ON borrowers.borrowers_id = borrowersp.borrowers_id 
LEFT JOIN tblborrowerskid as kid
ON borrowers.borrowers_id = kid.parent_id

WHERE borrowers.borrowers_id=23432413;

You can add as many as you'd need.

score 1 · Answer 2 · edited May 23 '17 at 11:57

Lets say you have tables : t1 ,t2 and t3 ..Left Joining :

SELECT        t2.id, t1.id AS Expr1
FROM            t3 LEFT JOIN
                         t1 ON t3.id = t1.id LEFT JOIN
                         t2 ON t1.id = t2.id

We can also write the above query with left outer join :

SELECT        t2.id, t1.id AS Expr1
FROM            t3 LEFT OUTER JOIN
                         t1 ON t3.id = t1.id LEFT OUTER JOIN
                         t2 ON t1.id = t2.id

For 5 tables ..t1,t2,t3,t4 and t5 :

SELECT        t2.id, t1.id AS Expr1, t5.id AS Expr2, t4.id AS Expr3
FROM            t5 LEFT OUTER JOIN
                         t1 ON t5.id = t1.id LEFT OUTER JOIN
                         t4 ON t1.id = t4.id LEFT OUTER JOIN
                         t3 ON t1.id = t3.id LEFT OUTER JOIN
                         t2 ON t1.id = t2.id

Please have a look at this SO post : What's the difference between INNER JOIN, LEFT JOIN, RIGHT JOIN and FULL JOIN?

Thank You sir utility :D – truelogicINC Aug 06 '15 at 02:57 — truelogicINC, Aug 06 '15 at 02:57

I Only Know 2 Tables in Left Join SQL Query. What if I have 3 or More Tables?

2 Answers2