I am joining 2 tables -tbl1 and tbl2. Left join give all data from tbl1 which is in tbl2 or only on tbl1. Right join gives data from tbl2 which is don't exists in tbl1.
I want to combine both results.
What is the best way to do this so that I get all data from tbl1 and tbl2?
The only you can do that is by using UNION. MySQL doesn't support FULL JOINjust like in MSSQL.
SELECT *
FROM tbl1 t1
LEFT JOIN tbl2 t2
ON t1.col = t2.col
UNION
SELECT *
FROM tbl1 t1
RIGHT JOIN tbl2 t2
ON t1.col>= t2.<col
SEE HERE: Simulating FULL JOIN in MYSQL
By the way, UNION has optional keyword ALL,when the ALL is omitted, UNION automatically selects DISTINCT rows from the resultset.
EXAMLE:
SELECT *
FROM tableA
UNION ALL
SELECT *
FROM tableA
this can result duplicates rows
ColA ColB
==================
1 John
2 Jade
2 Jade
3 Hello
BUT if you omit the word ALL
SELECT *
FROM tableA
UNION
SELECT *
FROM tableA
this can result distinct rows only
ColA ColB
==================
1 John
2 Jade
3 Hello
What you want is FULL JOIN
LEFT JOIN+RIGHT JOIN=FULL JOIN
So try this:
SELECT * FROM tbl1
LEFT JOIN tbl2 ON tbl1.id = tbl2.id
UNION
SELECT * FROM tbl1
RIGHT JOIN tbl2 ON tbl1.id = tbl2.id
The UNION clause combines the results of two SQL queries into a single table of all matching rows.
Here's an alternative that can be easily extended if you have a full join of more than 2 tables:
SELECT t1*, t2.*
FROM
( SELECT col
FROM tbl1
UNION
SELECT col
FROM tbl2
) AS d
LEFT JOIN tbl1 AS t1
ON t1.col = d.col
LEFT JOIN tbl2 AS t2
ON t2.col = d.col ;
you have to use FULL OUTER JOIN, But mysql doesnt support it.. You could do this for getting the result:
SELECT *
FROM tbl1 t1 LEFT JOIN tbl2 t2
ON t1.<col> = t2.<col>
UNION
SELECT *
FROM tbl1 t1 RIGHT JOIN tbl2 t2
ON t1.<col>= t2.<col>
