our company has an opening for a junior database administrator. As a senior database
administrator, your manager has developed the following questions to ask potential new hires
and he wants you to provide the answers to the following questions so they can be forwarded to
Human Resources: Explain Data Manipulation Language (DML). What is the difference between
Data Definition Language (DDL) and Data Control Languages (DCL)? Provide an example of an
SQL query that creates and executes four individual tables; Student, Class, InstructorID, and
Room Number with not null and default constraints.
Solution
Data Manupulation Language(DML):
-->It permits the users to manipulate data in database.
-->manupulation involves in inserting data into database tables,retrieving existing data,
deleting data from eisting tables and modifying existing data.
-->It is mostly incorporated in SQL databases.
-->SELECT,UPDATE,INSERT INTO,DELETE commands comes under DML.
------------------------------------------------------------------------------------------------------
DDL: Data definition language
-->It is used to define the database structure or schema.
1)CREATE-It is used to create objects in database
2)ALTER - It is used to alters the structure of the database
3)DROP - It is used to delete objects from the database
4)TRUNCATE -It is used to remove all records from a table, including all spaces allocated
for the records are removed
5)RENAME - It is used to rename an object
DCL:data control language
-->It is used to control the data in database
1)GRANT - It gives users access privileges to database.
2)REVOKE - It withdraw access privileges given with the GRANT command
----------------------------------------------------------------------------------------------------------
1)CREATE TABLE Student{
Student_name varchar(50) NOT NULL DEFAULT \'Mouni\',
Student_Id int NOT NULL DEFAULT 10
}
CREATE TABLE Class{
Class_name varchar(15) NOT NULL DEFAULT \'CSE\'
InstructorId int NOT NULL DEFAULT \'100\'
}
CREATE TABLE InstructorID{
InstructorID int NOT NULL DEFAULT \'100\'
Instructor_name varchar(15) NOT NULL DEFAULT \'Thomson\'
}
CREATE TABLE Room{
Room_number int NOT NULL DEFAULT \'12A\'
Room_naem varchar(10) DEFAULT \'omega\'
}.
our company has an opening for a junior database administrator. As a.pdf
1. our company has an opening for a junior database administrator. As a senior database
administrator, your manager has developed the following questions to ask potential new hires
and he wants you to provide the answers to the following questions so they can be forwarded to
Human Resources: Explain Data Manipulation Language (DML). What is the difference between
Data Definition Language (DDL) and Data Control Languages (DCL)? Provide an example of an
SQL query that creates and executes four individual tables; Student, Class, InstructorID, and
Room Number with not null and default constraints.
Solution
Data Manupulation Language(DML):
-->It permits the users to manipulate data in database.
-->manupulation involves in inserting data into database tables,retrieving existing data,
deleting data from eisting tables and modifying existing data.
-->It is mostly incorporated in SQL databases.
-->SELECT,UPDATE,INSERT INTO,DELETE commands comes under DML.
------------------------------------------------------------------------------------------------------
DDL: Data definition language
-->It is used to define the database structure or schema.
1)CREATE-It is used to create objects in database
2)ALTER - It is used to alters the structure of the database
3)DROP - It is used to delete objects from the database
4)TRUNCATE -It is used to remove all records from a table, including all spaces allocated
for the records are removed
5)RENAME - It is used to rename an object
DCL:data control language
-->It is used to control the data in database
1)GRANT - It gives users access privileges to database.
2)REVOKE - It withdraw access privileges given with the GRANT command
----------------------------------------------------------------------------------------------------------
1)CREATE TABLE Student{
Student_name varchar(50) NOT NULL DEFAULT 'Mouni',
Student_Id int NOT NULL DEFAULT 10
2. }
CREATE TABLE Class{
Class_name varchar(15) NOT NULL DEFAULT 'CSE'
InstructorId int NOT NULL DEFAULT '100'
}
CREATE TABLE InstructorID{
InstructorID int NOT NULL DEFAULT '100'
Instructor_name varchar(15) NOT NULL DEFAULT 'Thomson'
}
CREATE TABLE Room{
Room_number int NOT NULL DEFAULT '12A'
Room_naem varchar(10) DEFAULT 'omega'
}
