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Software Engineering vocabulary · Databases and Persistence

Inner join

Meaning in software engineering, with examples

nounCore term

In software engineering, inner join means: A join that returns only the rows that have a match in both tables; rows without a partner on the other side are left out.

In Turkish: iç birleştirme, inner join

How it is used

The default join: writing just JOIN means INNER JOIN. It is the right choice when every row must have a partner, for example orders with their customers. A common bug is losing rows because an inner join was used where a left join was needed.

Example sentences

  1. An inner join drops products that have never been ordered.

  2. The report shows fewer customers than expected because of the inner join on addresses.

Common collocations

  • inner join on
  • use an inner join
  • inner join two tables
  • JOIN ... ON
  • joinA SQL operation that combines rows from two or more tables using a related column, such as a customer ID. As a verb, to join tables means to combine them this way.
  • left joinA join that returns all rows from the first (left) table and the matching rows from the second; where there is no match, the second table's columns are NULL.
  • foreign keyA column in one table that points to the primary key of another table, linking the two and stopping you from storing references to rows that do not exist.
  • SELECT statementThe SQL statement that reads data from one or more tables and returns the matching rows without changing anything in the database.

This word in other fields

The same English word can have a different meaning in another field:

More terms: Databases and Persistence

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