SQL

Question 1

vertical bar | meaning

bar meaning

Answer 1

OR

Question 2

curly brackets {…} meaning

Answer 2

indicates a required element

Question 3

square bracket […] meaning

Answer 3

indicate an optional element or optional repetition

Question 4

SELECT description

Answer 4

selects specific columns

Question 5

FROM description

Answer 5

specifies the table(s)

Question 6

WHERE description

Answer 6

filters individual rows that are subject to some condition

Question 7

GROUP BY description

Answer 7

groups together rows with same column name

Question 8

HAVING description

Answer 8

filters groups that are subject to some condition

Question 9

ORDER BY description

Answer 9

specifies the order of the output

Question 10

SELECT everything query

Answer 10

SELECT (*) FROM table;

Question 11

IS NULL description

Answer 11

to test for empty values

Question 12

IS NOT NULL description

Answer 12

to test for non-empty values

Question 13

SELECT DISTINCT description

Answer 13

selects columns without the repetitive values

Question 14

AS description

Answer 14

renames a column

Question 15

LIKE description

Answer 15

to search for a specified pattern

Question 16

% meaning

Answer 16

0 or more characters

Question 17

_ meaning

Answer 17

any single character

Question 18

e.g S% meaning

Answer 18

any string starting with the letter “S”

Question 19

e.g S_ _ _ _

Answer 19

any 5 letter string starting with “S”

Question 20

e.g %S

Answer 20

any string ending with the letter “S”

Question 21

NOT LIKE description

Answer 21

to filter a pattern out

Question 22

ASC keyword

Answer 22

to specify ascending order

Question 23

DESC keyword

Answer 23

to specify descending order

Question 24

INSERT values into a table query

Answer 24

INSERT INTO table(column) VALUES (‘values’);

Question 25

INSERT columns into another table query

Answer 25

INSERT INTO table2 SELECT column FROM table1 WHERE condition;

Question 26

UPDATE query

Answer 26

UPDATE table SET column1 = value1 WHERE condition;

Question 27

SET description

Answer 27

specifies names of 1 or more columns that are to be updated

Question 28

DELETE query

Answer 28

DELETE FROM table WHERE condition;

Question 29

COUNT description

Answer 29

returns number of rows that match the specified criterion

Question 30

SUM description

Answer 30

returns sum of values in specified column

Question 31

AVG description

Answer 31

returns average value in the specified column

Question 32

MIN description

Answer 32

returns lowest value in specified column

Question 33

MAX description

Answer 33

returns highest value in specified column

Question 34

Which SQL aggregate functions can only apply to numeric and non-numeric fields?

Answer 34

COUNT, MIN, MAX

Question 35

Which SQL aggregate functions can only apply to numeric fields?

Answer 35

SUM and AVG

Question 36

DISTINCT has no effect with ___/___ but may have with ___/___

Answer 36

MIN/MAX, SUM/AVG

Question 37

SELECT DISTINCT query

Answer 37

SELECT DISTINCT column FROM table;

Question 38

AS query

Answer 38

SELECT columnName AS newName FROM table;

Question 39

COUNT query

Answer 39

SELECT COUNT (column) FROM table WHERE condition;

Question 40

SUM query

Answer 40

SELECT SUM (column) FROM table WHERE condition;

Question 41

AVG query

Answer 41

SELECT AVG (column) FROM table WHERE condition;

Question 42

GROUP UP query

Answer 42

SELECT column FROM table WHERE condition GROUP BY column;

Question 43

HAVING query

Answer 43

SELECT column FROM table WHERE condition HAVING condition;

Question 44

ORDER BY query

Answer 44

SELECT * FROM table ORDER BY column;

Question 45

ASC|DESC query

Answer 45

SELECT column FROM table ORDER BY column ASC|DESC

Question 46

IS NULL|IS NOT NULL query

Answer 46

SELECT column1 FROM table WHERE column2 IS NULL | IS NOT NULL;

Question 47

LIKE|NOT LIKE query

Answer 47

SELECT column1 FROM table WHERE column2 LIKE | NOT LIKE pattern;