- How does outer join work?
- What is the difference between where and having clauses?
- What is the function of the inner join?
- In which case would you use a full outer join?
- What is outer join with example?
- How does full join work?
- Why use outer join in SQL?
- What is equi join?
- What is a cross join?
- What is the difference between a join and outer join operation?
- What does full join do in SQL?
How does outer join work?
When performing an inner join, rows from either table that are unmatched in the other table are not returned.
In an outer join, unmatched rows in one or both tables can be returned..
What is the difference between where and having clauses?
WHERE Clause is used to filter the records from the table based on the specified condition. … HAVING Clause is used to filter record from the groups based on the specified condition.
What is the function of the inner join?
The INNER JOIN creates a new result table by combining column values of two tables (table1 and table2) based upon the join-predicate. The query compares each row of table1 with each row of table2 to find all pairs of rows which satisfy the join-predicate.
In which case would you use a full outer join?
We use a FULL OUTER JOIN in Oracle when we want all unmatched data from both tables. Explanation: Oracle9i also makes it possible for you to easily execute a full outer join, including all records from the tables that would have been displayed if you had used both LEFT OUTER JOIN or RIGHT OUTER JOIN clauses.
What is outer join with example?
The FULL OUTER JOIN returns a result set that includes rows from both left and right tables. When no matching rows exist for the row in the left table, the columns of the right table will have nulls. Similarly, when no matching rows exist for the row in the right table, the column of the left table will have nulls.
How does full join work?
A FULL JOIN returns all the rows from the joined tables, whether they are matched or not i.e. you can say a full join combines the functions of a LEFT JOIN and a RIGHT JOIN . Full join is a type of outer join that’s why it is also referred as full outer join. The following Venn diagram illustrates how full join works.
Why use outer join in SQL?
We use the SQL OUTER JOIN to match rows between tables. We might want to get match rows along with unmatched rows as well from one or both of the tables.
What is equi join?
An equi join is a type of join that combines tables based on matching values in specified columns. … The column names do not need to be the same. The resultant table contains repeated columns. It is possible to perform an equi join on more than two tables.
What is a cross join?
The CROSS JOIN is used to generate a paired combination of each row of the first table with each row of the second table. This join type is also known as cartesian join. … The main idea of the CROSS JOIN is that it returns the Cartesian product of the joined tables.
What is the difference between a join and outer join operation?
Joins in SQL are used to combine the contents of different tables. … 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.
What does full join do in SQL?
SQL FULL JOIN Statement FULL JOIN returns all matching records from both tables whether the other table matches or not. … These two: FULL JOIN and FULL OUTER JOIN are the same.