What is difference between outer join and inner join?
What is difference between outer join and inner join?
The biggest difference between an INNER JOIN and an OUTER JOIN is that the inner join will keep only the information from both tables that’s related to each other (in the resulting table). An Outer Join, on the other hand, will also keep information that is not related to the other table in the resulting table.
Is inner join faster than outer join?
In case there are a large number of rows in the tables and there is an index to use, INNER JOIN is generally faster than OUTER JOIN. Generally, an OUTER JOIN is slower than an INNER JOIN as it needs to return more number of records when compared to INNER JOIN.
Is there a difference between join and inner join?
Difference between JOIN and INNER JOIN JOIN returns all rows from tables where the key record of one table is equal to the key records of another table. The INNER JOIN selects all rows from both participating tables as long as there is a match between the columns.
Which is better join or inner join?
Although ‘join’ means the same as ‘Inner join’, a good developer should use clear syntaxes to avoid ambiguities. ‘Inner join’ is better, although it is equivalent to ‘join’ in performance as well as function.
Why use inner join?
You can use an INNER JOIN operation in any FROM clause. This is the most common type of join. Inner joins combine records from two tables whenever there are matching values in a field common to both tables. You can use INNER JOIN with the Departments and Employees tables to select all the employees in each department.
Why inner join is best?
While both queries are well-written, I would suggest that you always use INNER JOIN instead of listing tables and joining them in the WHERE part of the query. There are a few reasons for that: Readability is much better because the table used and related JOIN condition are in the same line.
Which join is most efficient?
TLDR: The most efficient join is also the simplest join, ‘Relational Algebra’.
Why use inner join in SQL?
Inner joins combine records from two tables whenever there are matching values in a field common to both tables. You can use INNER JOIN with the Departments and Employees tables to select all the employees in each department.
Is inner join more efficient?
There is not a “better” or a “worse” join type. They have different meaning and they must be used depending on it. In your case, you probably do not have employees with no work_log (no rows in that table), so LEFT JOIN and JOIN will be equivalent in results.