noun
outer join
In relational databases, a join that returns all rows from one table and matched rows from another, with NULLs where no match exists. Often specified as LEFT, RIGHT, or FULL outer join.
SQLで外部結合を使うと、片方のテーブルに一致する行がなくてもデータを取得できます。
Using an outer join in SQL, you can retrieve data even when there is no matching row in one of the tables.
noun
external coupling; external linkage
General engineering term for a connection or linkage between separate systems or components. Less common than the database sense; context usually makes the meaning clear.
この機械は外部結合によって別の装置と連動します。
This machine works together with another device through an external coupling.