inner join
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Related to inner join: outer join
inner join
(database)(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.
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.
This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)
join
In relational database management, to match one table (file) against another based on some condition creating a third table with data from the matching tables. For example, a customer table can be joined with an order table creating a table for all customers who purchased a particular product.The default type of join is known as an "inner" join. It produces a resulting record if there is a matching condition. For example, matching shipments with receipts would produce only those shipments that have been received. On the other hand, an "outer" join using that example would create a record for every shipment whether or not it was received. The data for received items would be attached to the shipments, and empty, or null, fields would be attached to shipments without receipts.
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| A Simple Join |
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| This example matches the sales table against the product table based on product number to derive the product description. |
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