Introduction to SQL Language

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What does DDL stand for in SQL?

Data Definition Language

Which command is used to create database objects like tables and views?

CREATE

What does DML stand for in SQL?

Data Manipulation Language

Which command is used to retrieve data from a database?

SELECT Signup and view all the answers

What does the INSERT command do in SQL?

Inserts data into a table Signup and view all the answers

What is the purpose of the MERGE command in SQL?

UPSERT operation (conditional INSERT/UPDATE) Signup and view all the answers

What was the original name of the language now known as SQL?

SEQUEL Signup and view all the answers

When was the first commercially available implementation of SQL introduced by Oracle?

1979 Signup and view all the answers

What does SQL stand for?

Structured Query Language Signup and view all the answers

Which organization standardized SQL as a language for managing data held in RDBMS?

ANSI (American National Standards Institute) Signup and view all the answers

Name some of the database programs that SQL works with.

DB2, MySQL, PostgreSQL, Oracle, SQLite, SQL Server, Sybase, MS Access Signup and view all the answers

What are some major keywords supported by SQL to comply with the ANSI standard?

SELECT, UPDATE, DELETE, INSERT, WHERE Signup and view all the answers

What does a RIGHT JOIN return in SQL?

All the rows from the right table even if there are no matches in the left table. Signup and view all the answers

What does a CROSS JOIN return in SQL?

Cartesian product of all rows in both tables being joined. Signup and view all the answers

How does the number of rows in a CROSS JOIN result get calculated?

By multiplying the number of rows in both tables being joined. Signup and view all the answers

What is the purpose of SQL aggregate functions?

To assist in summarizing large volumes of data by returning a single value. Signup and view all the answers

What does the AVG() function in SQL return?

The average value of a column. Signup and view all the answers

What does the COUNT() function in SQL return?

The number of rows in a column. Signup and view all the answers

What does the INTERSECT operator in SQL do?

It returns only those rows that appear in both tables and removes duplicate rows. Signup and view all the answers

When using INTERSECT ALL operator, does it remove duplicate rows?

No, the INTERSECT ALL operator does not remove duplicate rows. Signup and view all the answers

Explain the purpose of the EXCEPT operator in SQL.

It returns all rows from the first table that do not appear in the second table. Signup and view all the answers

What does the JOIN operator in SQL allow you to do?

It allows you to combine data from multiple tables based on a common column. Signup and view all the answers

What is another name for INNER JOIN in SQL?

Equi Join Signup and view all the answers

Which SQL JOIN operation supports INNER, OUTER, and CROSS types?

JOIN operator Signup and view all the answers

What is the purpose of operators in SQL?

To compare, evaluate or calculate values. Signup and view all the answers

Where are operators mostly used in SQL statements?

In the WHERE clause. Signup and view all the answers

What are compound conditions in SQL?

Simple conditions joined by logical operators. Signup and view all the answers

What does the SQL AND operator do?

Joins together two or more conditions and returns result only when all are true. Signup and view all the answers

What are the logical operators in SQL?

AND, OR, and NOT. Signup and view all the answers

Give an example of using the SQL AND operator in a query.

SELECT * FROM table WHERE customer_id = 'c10' AND product_id = 'p5'; Signup and view all the answers