SQL and Relational Databases

Question 1

Explain the concept of a database.

Answer 1

A database is an organized collection of data that is stored and managed in a structured way to allow easy access, retrieval, and manipulation. Databases are commonly used in software applications, websites, and systems that handle large amounts of information

Question 2

Explain the concept of a relational database.

Answer 2

A relational database is a type of database that organizes data into tables (also called relations) which are linked together based on defined relationships. The primary structure used to manage and store data in a relational database is tables that consist of rows (records) and columns (fields).

Question 3

What are the advantages of relational databases?

Answer 3

use of a relational database facilitates the elimination of data inconsistency and data redundancy.

Question 4

what sql query do you use to retrieve data from a relational database

Answer 4

SELECT
FROM
WHERE
ORDER BY…ASC | DESC

Question 5

what SQL query do you use to insert data into a relational database using the commands.

Answer 5

INSERT INTO table_name (column1, column 2 …)
VALUES (value1, value2 …)

Question 6

what sql query do you use to edit (update) and delete data in a database using the commands.

Answer 6

UPDATE table_name
SET column1 = value1, column2 = value2 …
WHERE condition

DELETE FROM table_name WHERE condition

Question 7

what is a primary key

Answer 7

A primary key is a unique identifier for a record in a database table. It ensures that each row in the table can be uniquely identified and prevents duplicate entries.

Question 8

what is a foreign key

Answer 8

is a column or a set of columns in a database table that establishes a link between the data in two tables. It references the primary key of another table to enforce referential integrity.

Question 9

what is a field

Answer 9

A field in a database is a single column within a table that represents a specific attribute or piece of information about the records in that table. Fields are the smallest unit of data in a database.

Question 10

what is a record

Answer 10

A record in a database is a single, complete set of data entries (or row) that contains information for all fields in a table.