Outer Joins are less common than Inner Joins, but still highly useful.
Three Types of Outer Joins:
In this video, we introduced three types of Outer Joins, but only showed examples of the Left Outer Join. This is because a few database engines, like SQLite, only support the Left Outer Join. Most other database systems support all three types.
Right Outer Joins are essentially the same thing as Left Outer Joins, but just specified in the opposite direction.
Full Outer Joins are functionally different in that you are guaranteed to get all rows from both tables. Full Outer Joins aren’t used as much in application or report coding as Inner and Left/Right Outer Joins, but can come in very handy when doing things like comparing data between two tables that are structurally similar.
See all of the SQL used in Querying Relational Databases in the Querying Relational Databases Cheat Sheet.
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