BCA RDBMS PRACTICAL NUMBER_1

PRACTICAL NUMBER_1 

➤Create tables named employee, department, Salary, Implement all DDL commands on it.

DDL (Data Definition Language) Commands are-

1. Create,
2. Alter table (to Add Column, to Modify Column and to DROP Column)
3. Rename
4. Truncate
5. Drop

1. Create table Command-->

SQL> connect ⤶

Enter user-name: system⤶

Enter password : password⤶

connected

SQL>Create table Employee ( Emp_Id int primary key, Name varchar(20) , age int, city varchar(30));⤶

Table Created.

SQL> Create table Department( DeptId int primary key, Dept_Name varchar(20));⤶

Table Created.

SQL> Create table Salary ( Emp_Id int, Salary numeric(10,2));⤶

Table Created.

DDL Commands-Create Table

2. (a) Alter Table Command to Add Column--> we use this command to add Mobile Column in Employee Table.

SQL> Alter table Employee ADD Mobile number(10);⤶

Table altered.

2. (b) Alter table Command to Modify Column--> we use this command to modify Name Column with Not Null Constraint.

SQL> Alter table Employee MODIFY Name varchar(20) not null;⤶

Table altered.

2. (c) Alter table Command to DROP Column--> we use this command to drop or destroy Name Column.

SQL> Alter table Employee DROP COLUMN Name;⤶

Table altered.

DDL Commands-Alter Table(Add Column, Modify Column or Drop Column)

3. Rename Command--> this command is used to Rename object and here we will rename Employee table name to Employee_Record.

SQL>rename Employee to Employee_Record;⤶

Table renamed.

4. TRUNCATE Command--> this command is used to delete data permanently. 

SQL>TRUNCATE Table Employee_Record;⤶

Table truncated.

5. DROP Command--> this command is used to drop table, view, user, sequence, synonym etc.

SQL>drop table Employee_Record;⤶

Table dropped.  

DDL Commands- Rename, Truncate, Drop