SQL Data Control Language
Data Control Language decides to whom should (which user) permit access privileges.
GRANT and REVOKE are the commands of DCL.
GRANT: It gives privileges to user.
REVOKE: It takes back privileges from granted user.
Data Query Language
Data Query Language does not make any changes in database. Neither schema level nor data level.
SELECT is a command of DQL.
SELECT: Retrieves data /records from table.
Syntax:
SELECT Column_1, Column 2, …..
FROM Table_name
[WHERE condition];
Example:
- Select Student_id , Student_name
From Student Where Student_id=’10’;
- Select Student_id , Student_name From Student;
Syntax:
SELECT * FROM Table_name [WHERE condition];
Example:
Select * From Student where Student_id=’10’;
- This query retrieves single record with all its attributes/columns.
- ‘* ‘Indicates all the fields/attributes/columns in the table.
- Where condition is specified for a particular record.
Syntax:
SELECT * FROM Table_name;
Example:
SELECT * FROM STUDENT;
It will retrieve all records and all the columns from the table.
Where condition is not specified to fetch a particular record.
