A SQL (Structured Query Language) query operation that combines records from two tables and returns them in a result set based on the values in the join fields. Without additional qualification, join usually refers to the join in which field values are equal. For example, customer and order tables are joined on a common field such as customer ID. The result set contains combined customer and order records in which the customer IDs are equal. The WHERE clause in the following SQL query shows joins that use the custID columns and orderID columns:
