When to use inner join and outer join in SQL?

In SQL, a join is used to compare and combine — literally join — and return specific rows of data from two or more tables in a database. An inner join finds and returns matching data from tables, while an outer join finds and returns matching data and some dissimilar data from tables.

What is the difference between inner join and left join in SQL?

There are different types of joins available in SQL: INNER JOIN: returns rows when there is a match in both tables. LEFT JOIN: returns all rows from the left table, even if there are no matches in the right table. RIGHT JOIN: returns all rows from the right table, even if there are no matches in the left table.

What is the difference between join and an outer join operation?

What is the difference between a join and an outer join operation? Explanation: The outer join operation preserves a few tuples that are otherwise lost in the join operation. Explanation: The full outer join operation preserves the tuples named on both the sides of the operation.

Is Outer join same as full outer join?

In outer joins, all the related data from both the tables are combined correctly, plus all the remaining rows from one table. In full outer joins, all data are combined wherever possible.

What is the difference between a join and an outer join operation?

What is the difference between a join and an outer join operation? Explanation: The outer join operation preserves a few tuples that are otherwise lost in the join operation. The outer join operation preserves the tuples to the right of the operation.

What is the difference between left join 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 the 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.

When should we use inner join?

Generally, we use INNER JOIN when we want to select only rows that match an ON condition. If no rows match the ON condition, then it will not return any results. This can be somewhat stricter than using a LEFT JOIN .

Is outer join and full join same?

The FULL OUTER JOIN keyword returns all records when there is a match in left (table1) or right (table2) table records. Tip: FULL OUTER JOIN and FULL JOIN are the same.

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 left and RIGHT OUTER JOIN?

There are three types of outer joins, left, right and full. A left outer join contains all records of the “left” table even if it has no matches in the “right” table specified in the join. A right outer join contains all records in the “right” able even if it has no matches in the “left” table.

What are the types of join in SQL?

There are 2 types of SQL JOINS INNER JOINS and OUTER JOINS. If you don’t put INNER or OUTER keywords in front of the SQL JOIN keyword, then INNER JOIN is used. In short “INNER JOIN” = “JOIN” (note that different databases have different syntax for their JOIN clauses).

What is RIGHT OUTER JOIN in SQL?

A RIGHT OUTER JOIN is one of the JOIN operations that allow you to specify a JOIN clause. It preserves the unmatched rows from the second (right) table, joining them with a NULL in the shape of the first (left) table. A LEFT OUTER JOIN B is equivalent to B RIGHT OUTER JOIN A, with the columns in a different order.