数据库的几个实验，包括数据库的定义实验，数据库的建立和维护实验，数据库的查询实验，数据库的视图操作实验，触发器、存储过程操作实验-Database of several experiments, including the definition of experimental database, database creation and maintenance of experiments, the database query experiments, experimental operation of the database views, triggers, stored procedures, operation of experimental