What is left outer join and right outer join?
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.
IS LEFT join outer or inner?
LEFT JOIN: This join returns all the rows of the table on the left side of the join and matching rows for the table on the right side of join. The rows for which there is no matching row on right side, the result-set will contain null. LEFT JOIN is also known as LEFT OUTER JOIN.
What is the difference between left right outer and inner join?
Inner join: Only show rows, when has it data from both of the tables. Outer join: (left/right): Show the all result from the left / right table with the paired row(s), if it exists or not.
What is between outer and inner?
The major difference between inner and outer joins is that inner joins result in the intersection of two tables, whereas outer joins result in the union of two tables. In this story, I will describe the difference between an inner join, full outer join, left outer join and right outer join.
What is right inner join?
(INNER) JOIN : Returns records that have matching values in both tables. RIGHT (OUTER) JOIN : Returns all records from the right table, and the matched records from the left table. FULL (OUTER) JOIN : Returns all records when there is a match in either left or right table.
When use left join and right join?
LEFT JOIN vs. RIGHT JOIN
|LEFT JOIN||RIGHT JOIN|
|It joins two or more tables, returns all records from the left table, and matching rows from the right-hand table.||It is used to join two or more tables, returns all records from the right table, and matching rows from the left-hand table.|
When to use inner join left join Right 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.
When to use inner join and outer 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.
What is right outer join in SQL?
A right outer join is a method of combining tables. The result includes unmatched rows from only the table that is specified after the RIGHT OUTER JOIN clause. If you are joining two tables and want the result set to include unmatched rows from only one table, use a LEFT OUTER JOIN clause or a RIGHT OUTER JOIN clause.
What is the difference between inner and 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.
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.
When to use left join?
A LEFT JOIN produces: Use an inner join when you want only the results that appear in both tables that matches the Join condition. 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.