Tutorials on Left, Right and Full Outer Join on MSC Notes

Tutorials on Left, Right and Full Outer Join on MSC Notes

 I also faced that type of problems but I studied different types of books and get their answers.

Ok now the answer of your question is that OUTER JOIN: In An outer join, rows are returned even when there are no matches through the JOIN criteria on the second table.

LEFT OUTER JOIN: A left outer join or a left join returns results from the table mentioned on the left of the join irrespective of whether it finds matches or not. If the ON clause matches 0 records from a table on the right, it will still return a row in the result – But with NULL in each column. RIGHT OUTER JOIN: A right outer join or a right join returns results from the table mentioned on the right of the join irrespective of whether it finds matches or not.

If the ON clause matches 0 records from the table on the left, it will still return a row in the result but with NULL in each column.

FULL OUTER JOIN: A full outer join will combine results of both left and right outer join.

Hence the records from both tables will be displayed with a NULL for missing matches from either of the tables.

Tutorials on Left, Right and Full Outer Join on MSC Notes

Only when there is a minimum of one row from both tables that fulfill's the join condition, inner joins return rows, and eliminate the ones that do not match with a row from the other table.

Tutorials on Left, Right and Full Outer Join on MSC Notes

When in SQL we are joining two tables and if one of these tables, one of the tables has such rows that do not have related rows in the other joined table and we still wanted to display all records we use outer joins.

Let for example we have two table students and courses, On the student table there are some student who have not yet taken any course and we still wanted to display all the students, even if the student has not course, we will use an outer join.

Left outer join Return all rows from the left table, even if there are no matches in the right table.

Left outer join Return all rows from the right table, even if there are no matches in the left table.

Full outer on display all the rows from both the tables, for example if there are some students having no courses and some courses that are not associated with any of the students , then all the students and all the courses will be displayed.

Tutorials on Left, Right and Full Outer Join on MSC Notes

Outer join: An outer join is a join that does not require the two joined tables to have a matching record. There are three types of outer join: 

Tutorials on Left, Right and Full Outer Join on MSC Notes

Hi,

For everybody, this is my solution.

If there any wrong then inform me.

Tutorials on Left, Right and Full Outer Join on MSC Notes

Hi,

Simply join is used to join content which is present in the two tables. But there should be one same column in both the tables.

Full outer joins:

It joins the both the tables,and it does not look for any matching.

Left outer join:

It gives only matching rows in both the tables and not matching rows in the left table means

( The table which is used first in the joint statement.)

Right outer join:

Reverse of the left.

Thanks

Anilkumar.

Tutorials on Left, Right and Full Outer Join on MSC Notes

Thank you all for this awesome help.

I clearly understand this now.

You guys rock.