Oracle common operating table structure of the sentence

First, a few words together to understand.

　　alter (change) rename (rename) column (columns, to describe the columns) modify (amend) comment on (review) truncate (cut, cut)

1. Create a table

　　create table table (1 Field 1 Field Name Type Default (is empty), 2 Field Name Field Type Default 2);

　　例：create table tab_person (id varchar2(50) default sys_guid() not null, mc varchar2(20) null,createtime date null);

2. Change the name of the table

　　alter table table name rename to new table name;

　　例：alter table tab_person rename to tab_people;

　　rename the new table name to the table name;

　　例：rename tab_people to tab_person;

3. Add Field

　　alter table add the table name field name field type;

　　例：alter table tab_person add sex varchar2(2);

4. Modify field name

　　alter table table name rename column field name to the new field name;

　　例：alter table tab_person rename column sex to xb;

5. Modify Field Type

　　alter table table name modify (new field name field type); // add matter seemingly without parentheses

　　例：alter table tab_person modify xb varchar2(4);

6. Delete field

　　alter table drop column table name field name;

　　例：alter table tab_person drop column xb;

7. Add / Modify / Delete Field Description

　　. Comment on column table name field name is 'table illustrates'; // delete it empty assignment

　　Example: comment on column tab_person.mc is 'name';

8. Empty the contents of the data table

　　truncate table 表名;

　　例：truncate table tab_person;

9. Delete table

　　drop table 表名;

　　例：drop table tab_person;