Table Commands
☞ Following are the topics to be covered :
1. Creating a Table
2. Viewing a Table Structure
3. Viewing a Table
4. Removing a Table
Creating a Table
☞ To create a table in RDBMS, we use CREATE TABLE command.
☞ Syntax :
CREATE TABLE <database_name>
(
<col1 > <type1>(size),
<col2 > <type2>(size),
<col3 > <type3>(size),
.......
) ;
☞ Example :
CREATE TABLE student
(
Rollno INTEGER NOT NULL PRIMARY KEY,
Name VARCHAR(50) NOT NULL,
Gender CHAR(1),
DOB DATE,
Fees DECIMAL(8,2)
) ;
OR
CREATE TABLE student
(
Rollno INTEGER NOT NULL,
Name VARCHAR(50) NOT NULL,
Gender CHAR(1),
DOB DATE,
Fees DECIMAL(8,2),
PRIMARY KEY(Rollno)
) ;
Viewing a Table Structure
☞ To view a table structure in RDBMS, we use DESCRIBE / DESC command.
☞ Syntax :
DESCRIBE <table_name> ;
OR
DESC <table_name> ;
☞ Example :
DESCRIBE student ;
OR
DESC student ;
Viewing a Table
☞ To verify that the table is created in RDBMS, we use SHOW TABLES command.
☞ Syntax :
SHOW TABLES ;
☞ Example :
SHOW TABLES ;
Removing a Table
☞ To permanently remove a table which is not in use from RDBMS, we use DROP TABLE command.
☞ Syntax :
DROP TABLE <table_name> ;
☞ Example :
DROP TABLE student ;
