数据库/表的基本操作和表级约束。利用图形用户界面创建，备份，删除和还原数据库和数据表。利用SQL语言创建和删除数据 库和数据表。-The basic operation of the database/table and table-level constraints. Using a graphical user interface to create, backup, delete and restore the database and data table. Create and del