Microsoft introduced the APPLY operator in SQL Server 2005. This under-used, non-standard operator can help us solve a number of common (and not-so-common) problems with elegant code which performs well. We will look several problem spaces in which the APPLY operator shines, such as joining to table-valued functions, getting the top N child records for each parent record, string splitting, and word matching. With the use of these examples, we will gain a deeper understanding of when to use the APPLY operator.

Comments

Comments are closed.