The joins produce a powerful data set which gives up to 16 rows of data sets, often much more than is anticipated. Although you get a massive amount of data sets, these joins are extremely dangerous as a slight incompatibility can cripple the entire system. If you are dealing with a project that also seeks the compatibility of Microsoft SQL server, then there will be benefits derived from the use of the left outer join.
The return sequence starts off with inner records being returned first, followed by right join records and finally a join of the left records. Use of the left join or left outer join statement in the SQL environment will refer to the exact same statement. This in essence means that there is no difference as to the result expected whether a left join is used or a left outer join is used.
The result will be similar, unless the environment is in the Microsoft SQL server. The outer keyword can be used or even omitted without worry as the results do not differ in any way. An inner join only produces a set of records that is present in two tables that are being compared. An outer join produces the complete set of all the records present in both tables under study. There is a notable difference where left join and left outer join used when using Microsoft SQL server.
All in all, use of the left join or left outer join statement refers to the exact same statement. Since there is no difference, the use of the left outer join is recommended.
Difference Between Similar Terms and Objects. Working examples of each query have been provided via SQL Fiddle. This tool will allow for hands on manipulation of the query. Left Join and Left Outer Join. Right Join and Right Outer Join. I'm a PostgreSQL DBA, as far as I could understand the difference between outer or not outer joins difference is a topic that has considerable discussion all around the internet.
Until today I never saw a difference between those two; So I went further and I try to find the difference between those. At the end I read the whole documentation about it and I found the answer for this,. Now they make perfect sense. Let's explain why this vocabulary. The vocabulary, the way teachers explain this, as well as some answers above, often make it looks like there are lots of different types of join. But it's actually very simple. This is basically joining a table to itself using one of the above joins.
I find APPLY operator very beneficial as they give better performance than having to do the same computation in a subquery. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams?
Collectives on Stack Overflow. Learn more. Asked 12 years, 10 months ago. Active 2 years, 3 months ago. Viewed 1. Quiver 1, 3 3 gold badges 29 29 silver badges 49 49 bronze badges. Venn diagrams are not appropriate for answers to this question.
The answer to this question is None. See the first comment. Venn diagrams illustrate the difference in output rows for special cases of inner vs outer join. See my comments here re other Venn diagram abuses. Add a comment. Active Oldest Votes. WBT 1, 3 3 gold badges 23 23 silver badges 34 34 bronze badges. Similarly, when no matching rows exist for the row in the right table, the columns of the left table are null padded. Full outer join is the union of left outer join and right outer join.
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