What is the difference between left and left outer join?
There really is no difference between a LEFT JOIN and a LEFT OUTER JOIN. Both versions of the syntax will produce the exact same result in PL/SQL. Some people do recommend including outer in a LEFT JOIN clause so it’s clear that you’re creating an outer join, but that’s entirely optional.
What is difference between left join and right join?
The LEFT JOIN includes all records from the left side and matched rows from the right table, whereas RIGHT JOIN returns all rows from the right side and unmatched rows from the left table.
What is the difference between right join and right outer join?
There is no difference between RIGHT JOIN and RIGHT OUTER JOIN . Both are the same. That means that LEFT JOIN and LEFT OUTER JOIN are the same.
What is difference between join and left join?
The LEFT JOIN statement is similar to the JOIN statement. The main difference is that a LEFT JOIN statement includes all rows of the entity or table referenced on the left side of the statement. A simple JOIN statement would only return the Authors who have written a Book.
Why LEFT join is called left outer join?
SQL left outer join is also known as SQL left join. Suppose, we want to join two tables: A and B. SQL left outer join returns all rows in the left table (A) and all the matching rows found in the right table (B). It means the result of the SQL left join always contains the rows in the left table.
Why use right join instead of left join?
The only reason I can think of to use RIGHT OUTER JOIN is to try to make your SQL more self-documenting. You might possibly want to use left joins for queries that have null rows in the dependent (many) side of one-to-many relationships and right joins on those queries that generate null rows in the independent side.
What is the difference between join and left join?
Why use left join and right join?
A left join is used when a user wants to extract the left table’s data only. Left join not only combines the left table’s rows but also the rows that match alongside the right table. 2. Right join combines the data of the right table and the rows that match both the tables.
What is the difference between minus and left join?
a JOIN finds rows that are matched between the two tables. A MINUS finds rows that exist in the first table but do not exist in the second table.
What is the difference between full outer join and outer join?
Left Outer Join: Returns all the rows from the LEFT table and matching records between both the tables. Right Outer Join: Returns all the rows from the RIGHT table and matching records between both the tables. Full Outer Join: It combines the result of the Left Outer Join and Right Outer Join.
Is Right Join opposite of left join?
RIGHT [OUTER] JOIN In the opposite of LEFT JOIN , RIGHT JOIN returns all records from the right table (table2) that matched the ON condition.
Why do inner join vs left join?
You’ll use INNER JOIN when you want to return only records having pair on both sides , and you’ll use LEFT JOIN when you need all records from the “left” table, no matter if they have pair in the “right” table or not.
What is the point of a LEFT OUTER JOIN?
LEFT OUTER JOIN. A LEFT OUTER JOIN is one of the JOIN operations that allow you to specify a join clause. It preserves the unmatched rows from the first (left) table, joining them with a NULL row in the shape of the second (right) table.
What is the difference between outer join and FULL OUTER JOIN?
The difference between inner join and outer join is as follow: Inner join is a join that combined tables based on matching tuples, whereas outer join is a join that combined table based on both matched and unmatched tuple.
What is the difference between left and right join?
There’s not much difference between a left join join and a right join in SQL. Both are outer joins, meaning the result includes all rows from one of the joined tables, even if a given row has no match in the other joined table. But the difference between left and right join is whether the left or right table is the one from which you get all rows.