What is left and right outer join in SQL?
There are two kinds of OUTER joins in SQL, LEFT OUTER join and RIGHT OUTER join. LEFT outer join includes unmatched rows from the table written on the left of the join predicate. On the other hand, RIGHT OUTER join, along with all matching rows, includes unmatched rows from the right side of the table.
What is the function of a left outer join?
What is the function of a left outer join? Explanation: The left outer join operation preserves the tuples named before the operation.
Is right outer join same as LEFT join?
The main difference between the Left Join and Right Join lies in the inclusion of non-matched rows. Left outer join includes the unmatched rows from the table which is on the left of the join clause whereas a Right outer join includes the unmatched rows from the table which is on the right of the join clause.
What is the difference between left outer join 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. See you in the next lesson.
How use left join in SQL?
The LEFT JOIN keyword returns all records from the left table (table1), and the matching records from the right table (table2). The result is 0 records from the right side, if there is no match.
How to use multiple left joins in SQL?
What does LEFT OUTER JOIN mean?
LEFT OUTER JOIN operation. 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 left and right join?
– Left Outer Join: Left Outer Join returns all the rows from the table on the left and columns of the table on the right is null padded. – Right Outer Join: Right Outer Join returns all the rows from the table on the right and columns of the table on the left is null padded. – Full Outer Join: Full Outer Join returns all the rows from both the table.
How to use outer join?
Using a NOT IN statement Using an OUTER APPLY Using a LEFT OUTER JOIN Using an EXCEPT statement Using NOT EXISTS All these approaches might yield the same result, however, it is possible that one