DML (INSERT, UPDATE, DELETE) in DBMS Theory - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does DML stand for in databases?

DML stands for Data Manipulation Language. It is used to add, change, or remove data in a database.

beginner

What is the purpose of the INSERT statement?

The INSERT statement adds new rows of data into a table in the database.

beginner

How does the UPDATE statement work?

UPDATE changes existing data in one or more rows of a table based on a condition.

beginner

What does the DELETE statement do?

DELETE removes one or more rows from a table based on a specified condition.

intermediate

Why is it important to use conditions with UPDATE and DELETE?

Conditions limit which rows are changed or removed. Without conditions, all rows could be affected, causing data loss.

Which DML command is used to add new data to a table?

A INSERT

B UPDATE

C DELETE

D SELECT

INSERT adds new rows to a table.

What happens if you run DELETE without a WHERE condition?

A Deletes only the first row

B Deletes all rows in the table

C Deletes no rows

D Returns an error

Without WHERE, DELETE removes every row in the table.

Which statement changes existing data in a table?

A UPDATE

B CREATE

C DELETE

D INSERT

UPDATE modifies existing rows based on conditions.

What is the main risk of running UPDATE without a WHERE clause?

A No rows will be updated

B Only one row will be updated

C All rows will be updated

D The table structure will change

Without WHERE, UPDATE affects every row in the table.

Which DML command would you use to remove a specific record?

A ALTER

B UPDATE

C INSERT

D DELETE

DELETE removes rows from a table based on conditions.

Explain the differences between INSERT, UPDATE, and DELETE commands in DML.

Think about how each command affects the data in a table.

Why should you be careful when using UPDATE or DELETE without a WHERE clause?

Consider what happens if no limits are set on these commands.