Data3 HK 2017

Accessing data with SQL becomes more and more important. For resolving a single request data located in multiple tables must be filtered, accumulated and/or merged together. In this way we need to focus our attention on consolidating data split over multiple tables. SQL provides different methods for joining tables and views together, such as inner, outer, exception, cross and full join. A table or view even can be joined with itself or with the result of a different select statement. The result returned from multiple select statements can be merged and even accumulated in a single SQL statement.