Learning SQLite

Question 1

What is a relational database?

Answer 1

A database that organizes information into one or more tables.

Question 2

What is a table?

Answer 2

A collection of data organized into rows and columns.

Question 3

All data stored in a relational database is of a certain data type. Some of the most common data types are:

Answer 3

INTEGER, a positive or negative whole number
TEXT, a text string
DATE, the date formatted as YYYY-MM-DD
REAL, a decimal value

Question 4

What is a SQL statement?

Answer 4

A string of characters that the database recognizes as a valid command and always ends in a semicolon ;

Question 5

What is a clause?

Answer 5

Perform specific tasks in SQL. By convention, these are written in capital letters and can also be referred to as commands.

Question 6

What is a parameter?

Answer 6

A list of columns, data types, or values that are passed to a clause as an argument.

Question 7

UPDATE clause

Answer 7

A clause that edits a row in the table.

Question 8

SET clause

Answer 8

A clause that indicates the column to edit.

Question 9

DELETE FROM clause

Answer 9

A clause that lets you delete rows from a table.

Question 10

WHERE clause

Answer 10

A clause that lets you select which rows you want to delete.

Question 11

What are constraints?

Answer 11

Used to tell the database to reject inserted data that does not adhere to a certain restriction.

Question 12

What is SQL?

Answer 12

A programming language designed to manipulate and manage data stored in relational databases.

Question 13

What is a relational database?

Answer 13

A database that organizes information into one or more tables.

Question 14

CREATE TABLE clause

Answer 14

A clause that creates a new table.

Question 15

INSERT INTO clause

Answer 15

A clause that adds a new row to a table.

Question 16

SELECT clause

Answer 16

A clause that queries data from a table.

Question 17

ALTER TABLE clause

Answer 17

A clause that changes an existing table.

Question 18

UPDATE clause

Answer 18

A clause that edits a row in a table.

Question 19

DISTINCT statement

Answer 19

Used to return unique values in the output. It filters out all duplicate values in the specified column(s).

Question 20

%

Answer 20

A wildcard character that matches zero or more missing letters in the pattern.

Question 21

ORDER BY

Answer 21

A clause that indicates you want to sort the result set by a particular column.

Question 22

LIMIT clause

Answer 22

A clause that lets you specify the maximum number of rows the result set will have.

Question 23

CASE

Answer 23

A statement that allows us to create different outputs (usually in the SELECT statement). It is SQL’s way of handling if-then logic.

Question 24

Aggregates

Answer 24

Calculations performed on multiple rows of a table.

Question 25

GROUP BY

Answer 25

A clause in SQL that is used with aggregate functions. It is used in collaboration with the SELECT statement to arrange identical data into groups.