Database - standard language SQL

1. Complete the core function of only nine verbs:

Data query; SELECT

Data Definition: CREATE, DROP, ALTER;

Data manipulation: insert, delete, update

Data control; grant, remove

2. supports three modes structure

View - Mode outer
base table (set) - mode
storage file and the index mode ---

 

3. define and modify the base table (defined mode):

CREATE TABLE

TABLE the DROP
the ALTER TABLE
define the view (defined mode):

The VIEW the CREATE
the DROP the VIEW
defined index (defined in the mode):

INDEX the CREATE
DROP INDEX
Description: A view is derived from the basic table virtual tables, indexes depends on the base tables,
SQL does not modify the operating view and index, by first deleting and then create
this purpose.