PL/SQL Create table

In Oracle PL/SQL, the CREATE TABLE statement is used to create a new table in a database. The basic syntax for creating a table is as follows:

CREATE TABLE table_name
(
   column1 datatype constraint,
   column2 datatype constraint,
   column3 datatype constraint,
   ....
);

table_name is the name of the table that you want to create.
column1, column2, column3, etc. are the names of the columns in the table.
datatype is the data type for each column (e.g. NUMBER, VARCHAR2, DATE, etc.).
constraint is any constraints you want to apply to the column (e.g. NOT NULL, UNIQUE, PRIMARY KEY, etc.).

Create sequence

CREATE SEQUENCE course_seq 
MINVALUE 1 
MAXVALUE 999999999999999999999999999 
START WITH 1 
INCREMENT BY 1 
CACHE 20;

Create table

CREATE TABLE course(
course_id NUMBER NOT NULL,
name VARCHAR2(250) NOT NULL,
description VARCHAR2(4000),
duration VARCHAR2(25),
price NUMBER,
CONSTRAINT pk_course_id PRIMARY KEY(course_id)
);

Create trigger

CREATE OR REPLACE TRIGGER course_t1
  BEFORE INSERT ON course
  FOR EACH ROW
DECLARE
BEGIN
  IF :new.course_id IS NULL THEN
    SELECT course_seq.nextval INTO :new.course_id FROM dual;
  END IF;
END;

Insert into table

SET DEFINE OFF;
Insert into COURSE (NAME,DESCRIPTION,DURATION,PRICE) values ('SQL 1','SQL course for beginners','1 week',10);
Insert into COURSE (NAME,DESCRIPTION,DURATION,PRICE) values ('SQL 2','SQL course for advanced','2 weeks',50);
Insert into COURSE (NAME,DESCRIPTION,DURATION,PRICE) values ('HTML5','Learn HTML 5','1 week',10);
Insert into COURSE (NAME,DESCRIPTION,DURATION,PRICE) values ('PHP','PHP course','4 weeks',75);
Insert into COURSE (NAME,DESCRIPTION,DURATION,PRICE) values ('CSS','Learn CSS','2 weeks',20);
COMMIT;

Create table backup

CREATE TABLE course_backup AS SELECT * FROM course;

COURSE_ID	NAME	DESCRIPTION	DURATION	PRICE
1	SQL 1	SQL course for beginners	1 week	10
2	SQL 2	SQL course for advanced	2 week	50
3	HTML5	Learn HTML 5	1 week	10
4	PHP	PHP course	4 week	75
5	CSS	Learn CSS	2 week	20

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