Is left outer join better than inner join?
A LEFT JOIN is absolutely not faster than an INNER JOIN . In fact, it’s slower; by definition, an outer join ( LEFT JOIN or RIGHT JOIN ) has to do all the work of an INNER JOIN plus the extra work of null-extending the results.
Is GroupJoin a left join?
This is actually not nearly as crazy as it seems. Basically GroupJoin does the left outer join, the SelectMany part is only needed depending on what you want to select.
When to use left outer join vs inner join?
A inner join only shows rows if there is a matching record on the other (right) side of the join. A (left) outer join shows rows for each record on the left hand side, even if there are no matching rows on the other (right) side of the join.
IS LEFT join default inner or outer?
INNER is the default; LEFT , RIGHT , and FULL imply an outer join.”
When to use an outer join?
An outer join is used to return results by combining rows from two or more tables. But unlike an inner join, the outer join will return every row from one specified table, even if the join condition fails.
When to use left join?
Use a left join when you want all the results from Table A, but if Table B has data relevant to some of Table A’s records, then you also want to use that data in the same query. Use a full join when you want all the results from both Tables.
What is left and RIGHT OUTER JOIN?
The key difference between a left outer join, and a right outer join is that in a left outer join it’s the table in the FROM clause whose all rows are returned. Whereas, in a right outer join we are returning all rows from the table specified in the join clause.
What is left and right join?
A left join refers to keeping all of the records from the 1st table irrespective of result, and the insertion of NULL values when the second table values do not match. A right join, on the other hand, refers to keeping all of the records coming from the 2nd table irrespective of what the result is,…