"You canker blossom!" 3 Shakespearean Insults
(Commonly "join", but see also "outer join") A relational database operation which selects rows from two tables such that the value in one column of the first table also appears in a certain column of the second table.
An example in SQL:
select * from A, B where A.x = B.y
The column names (x and y in this example) are often, but not necessarily, the same.