Top "Left-join" questions

A left join is an outer join which generates a result that contains all the records of the "left" table even when there are no matching records in other tables taking part in the join.

MySQL 5 left join unknown column

I had the below query working in mysql 4.1, but does not in 5.0: SELECT * FROM email e, event_email ee LEFT …

mysql left-join mysql-error-1054
Where to use Outer Apply

MASTER TABLE x------x--------------------x | Id | Name | x------x--------------------x | 1 | A | | 2 | B | | 3 | C | x------x--------------------x DETAILS TABLE x------x--------------------x-------x | Id | PERIOD | QTY | x------x--------------------x-------x | 1 | 2014-01-13 | 10 | | 1 | 2014-01…

sql-server sql-server-2008 left-join outer-apply
SQLDF Left Join in R

My goal is to take 'matr', sort it by column c1, and keep unique(c1) where c2 = 1. For example, from …

r left-join sqldf
mysql: why does left join not use an index?

I am facing a strange performance issue with a mysql query. SELECT `pricemaster_products`.*, `products`.* FROM `pricemaster_products` LEFT JOIN `…

mysql join left-join inner-join
Alias a table in Knex

I have a SQL query that refers to the same table twice, and I need to alias the table to …

sql left-join inner-join knex.js
How to left join or inner join a table itself

I have this data in a table, for instance, id name parent parent_id 1 add self 100 2 manage null 100 3 add 10 200 4 manage …

mysql sql left-join inner-join self-join
Group by Multiple Columns and Count

I have Table1 and Table2 in the form of IEnumerable<DataRow>. Both the tables have columns Column1 and …

linq count left-join linq-group
Can I perform this Android query with ContentResolver.query()? (LEFT JOIN and CASE)

I am looking to perform the following query (in pseudo-code) on Android: SELECT C.ID, C.NAME, CASE ISNULL(G.…

android sql left-join android-contacts android-contentresolver
Left Join not returning all rows

I have this query in MySQL: SELECT pr.*, pr7.value AS `room_price_high` FROM `jos_hp_properties` pr LEFT …

mysql left-join
Join statement order of operation

Given the following 3 way join select t1.* from t1 left join t2 on t1.fk = t2.pk join t3 on …

sql sql-server tsql join left-join