by The Structure of Create Table Command
Table name is Student
| Column name | Data type | Size |
| Reg_no | varchar2 | 10 |
| Name | char | 30 |
| DOB | date | |
| Address | varchar2 | 50 |
Insert
The ALTER Table Command
By The use of ALTER TABLE Command we can modify our exiting table.
Adding New Columns
Syntax:
ALTER TABLE <table_name>
ADD (<NewColumnName> <Data_Type>(<size>),……n)
Example:
ALTER TABLE Student ADD (Age number(2), Marks number(3));
The Student table is already exist and then we added two more columns Age and Marks respectively, by the use of above command.
Delete
Syntax:
DROP TABLE <table_name>
Example:
DROP TABLE Student;
It will destroy the table and all data which will be recorded in it.
Update
UPDATE Syntax
UPDATE table_name
SET column1 = value1, column2 = value2, …
WHERE condition;
