SQL and SQL Server

SQL--the international standard language of relational databases.

SQL Server-a well-known database management system. Other well-known database management systems include Oracle, Sybase, and so on, all of which implement the SQL language.

In SQL, complete all core functions using only the 9 verbs shown in the following table:

SQL features           verbs

Data definition         Create (creation)          DROP (cancel)            alter (change) Data Update          insert                     update                   DELETE Data query         SELECT Data Control          grant                      REVOKE

SQL supports a three-level schema structure in which the view corresponds to the outside mode, the base table corresponds to the logical mode, and the storage file corresponds to the internal mode.

There are 3 basic types of relational tables that appear in SQL databases: Basic tables, view charts, and export tables.

Basic table : The table that is actually stored in the database is the "real table";

View Chart : A table consisting of one or more basic tables and other views, which is a "virtual table";

Export Table : The table that was generated because the query was executed.