Basic SQL Definitions

Question 1

This lets you add columns to a table in a database.

Answer 1

ALTER TABLE

Question 2

This is an operator that combines two conditions. Both conditions must be true for the row to be included in the result set.

Answer 2

AND

Question 3

This is a keyword in SQL that allows you to rename a column or table using an alias.

Answer 3

AS

Question 4

This is an aggregate function that returns the average value for a numeric column.

Answer 4

AVG()

Question 5

This operator is used to filter the result set within a certain range. The values can be numbers, text or dates

Answer 5

BETWEEN

Question 6

These statements are used to create different outputs (usually in the SELECT statement). It is SQL’s way of handling if-then logic.

Answer 6

CASE

Question 7

This is a function that takes the name of a column as an argument and counts the number of rows where the column is not NULL.

Answer 7

COUNT()

Question 8

This creates a new table in the database. It allows you to specify the name of the table and the name of each column in the table.

Answer 8

CREATE TABLE

Question 9

These statements are used to remove rows from a table.

Answer 9

DELETE

Question 10

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

Answer 10

GROUP BY

Question 11

This was added to SQL because the WHERE keyword could not be used with aggregate functions.

Answer 11

HAVING

Question 12

This will combine rows from different tables if the join condition is true.

Answer 12

INNER JOIN

Question 13

These statements are used to add a new row to a table.

Answer 13

INSERT

Question 14

These are operators used with the WHERE clause to test for empty values.

Answer 14

IS NULL and IS NOT NULL

Question 15

This is a special operator used with the WHERE clause to search for a specific pattern in a column.

Answer 15

LIKE

Question 16

This is a clause that lets you specify the maximum number of rows the result set will have.

Answer 16

LIMIT

Question 17

This is a function that takes the name of a column as an argument and returns the largest value in that column.

Answer 17

MAX()

Question 18

This is a function that takes the name of a column as an argument and returns the smallest value in that column.

Answer 18

MIN()

Question 19

This is an operator that filters the result set to only include rows where either condition is true.

Answer 19

OR

Question 20

This is a clause that indicates you want to sort the result set by a particular column either alphabetically or numerically.

Answer 20

ORDER BY

Question 21

This will combine rows from different tables even if the join condition is not met. Every row in the left table is returned in the result set, and if the join condition is not met, then NULL values are used to fill in the columns from the right table.

Answer 21

OUTER JOIN

Question 22

This is a function that takes a column name and an integer as an argument. It rounds the values in the column to the number of decimal places specified by the integer.

Answer 22

ROUND()

Question 23

These statements are used to fetch data from a database. Every query will begin with this command.

Answer 23

SELECT

Question 24

This specifies that the statement is going to be a query that returns unique values in the specified column(s).

Answer 24

SELECT DISTINCT

Question 25

This is a function that takes the name of a column as an argument and returns the sum of all the values in that column.

Answer 25

SUM()

Question 26

These statements allow you to edit rows in a table.

Answer 26

UPDATE

Question 27

This is a clause that indicates you want to filter the result set to include only rows where the following condition is true.

Answer 27

WHERE

Question 28

This clause lets you store the result of a query in a temporary table using an alias. You can also define multiple temporary tables using a comma and with one instance of the keyword.

This clause is also known as common table expression (CTE) and subquery factoring.

Answer 28

WITH