New Development Features

SQL 2000 provides numerous features to make it easier to write stored procedures and triggers (code that runs on the database server). Many of these features have already proven their worth in competing database management systems. Taken together, these features will make it more feasible to do “programming in the large”—to write and debug large program modules. Among the most important new features:

Cascading deletes and updates. SQL 2000 can automatically make adjustments to the database to enforce referential integrity constraints after updates or deletes. For example, if an application deletes a purchase order entry in a table, SQL Server can “cascade” that delete to a separate table that holds the purchase order’s line items, automatically deleting entries for items in the order. Cascading deletes and updates are standard features of many database servers, but new to SQL Server. SQL 7 can enforce referential integrity constraints, but only by aborting transactions that try to make changes that would violate the constraints; it can’t automatically cascade updates or deletes to related tables.