SQL Server developers and administrators are no strangers to Data Transformation Services (DTS) packages. They likely develop DTS packages to perform everything from simple database operations to data aggregation. As such, when they upgrade some or a

、掌握基本查询 2、掌握嵌套查询 3、量词与谓词的应用 4、利用聚合函数进行数据统计 -To master the basic query 2, have nested query 3, quantifiers and predicate the application of 4, the use of data aggregation function