# LEFT and RIGHT JOINS reverse behavior for some tables

**URL:** <https://community.cratedb.com/t/left-and-right-joins-reverse-behavior-for-some-tables/112>\
**Category:** SQL\
**Created:** [January 15, 2019, 9:50pm UTC](https://community.cratedb.com/t/left-and-right-joins-reverse-behavior-for-some-tables/112 "2019-01-15T21:50:32Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![bpiel](https://sea2.discourse-cdn.com/flex020/user_avatar/community.cratedb.com/bpiel/32/61_2.png) [@bpiel](https://community.cratedb.com/u/bpiel)\
**Post date:** [January 15, 2019, 9:50pm UTC](https://community.cratedb.com/t/left-and-right-joins-reverse-behavior-for-some-tables/112/1 "2019-01-15T21:50:32Z")

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It seems like the behavior of LEFT vs RIGHT JOINS can flip, depending on which tables I’m querying.  
Any idea what’s going on? thanks

```
cr> select "test1"."id" "a", "test2"."id" "b" from "test1" left join "test2" on 1=2;
+---+------+
| a | b |
+---+------+
| 3 | NULL |
+---+------+
SELECT 1 row in set (0.003 sec)
cr> select "test1"."id" "a", "test2"."id" "b" from "test1" right join "test2" on 1=2;
+------+---+
| a | b |
+------+---+
| NULL | 5 |
+------+---+
SELECT 1 row in set (0.001 sec)
cr> select "orgs"."org-name", "sessions"."user-id" from orgs left join sessions on 1=2;
+----------+--------------------+
| org-name | user-id |
+----------+--------------------+
| NULL | UUID-users-a@f.com |
+----------+--------------------+
SELECT 1 row in set (0.001 sec)
cr> select "orgs"."org-name", "sessions"."user-id" from orgs right join sessions on 1=2;
+-------------+---------+
| org-name | user-id |
+-------------+---------+
| Buyer Org 1 | NULL |
| Vendor Org2 | NULL |
+-------------+---------+
SELECT 2 rows in set (0.003 sec)
```

---

<div class="post-metadata">

**Author:** ![yash](https://avatars.discourse-cdn.com/v4/letter/y/f17d59/32.png) [@yash](https://community.cratedb.com/u/yash)\
**Post date:** [January 23, 2019, 5:51am UTC](https://community.cratedb.com/t/left-and-right-joins-reverse-behavior-for-some-tables/112/2 "2019-01-23T05:51:40Z")

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Hi,

LEFT JOIN and RIGHT JOIN are showing the expected behavior for the table design. After looking at the above queries, I guess they might be missing a common field or relation between the two tables. Our documentation for JOINS is available here - [https://crate.io/docs/crate/reference/en/latest/general/dql/joins.html?highlight=joins#right-outer-joins](https://crate.io/docs/crate/reference/en/latest/general/dql/joins.html?highlight=joins#right-outer-joins)  
[https://crate.io/docs/crate/reference/en/latest/general/dql/joins.html?highlight=joins#left-outer-joins](https://crate.io/docs/crate/reference/en/latest/general/dql/joins.html?highlight=joins#left-outer-joins)  
Kindly refer to the example of Employee, Department tables in above and let us know if it helps.

Thanks.