Building a table in SQL language, lesson 1

--Delete Table
--drop table teachers;
--Create a table
CREATE TABLE Teachers
(
TNO VARCHAR2 (6) NOT NULL,
Tname VARCHAR2 (8) NOT NULL,
Tsex VARCHAR2 (4) NOT NULL,
TSR Date,
Pro VARCHAR2 (10),
Depa VARCHAR2 (14)
);

--Add comments
Comment on column Teachers.tno
Is ' teacher number (primary key) ';
Comment on column teachers.tname
Is ' teacher name ';
Comment on column teachers.tsex
Is ' teacher gender ');
Comment on column TEACHERS.TSR
Is ' teacher's birthday ';
Comment on column Teachers.pro
Is ' teacher title) ';
Comment on column Teachers.depa
Is ' teacher Department ');

--Add a PRIMARY KEY constraint
--alter the meaning of the modification
ALTER TABLE teachers add constraint pk_teachers primary key (TNO);

Building a table in SQL language, lesson 1