SQL Flashcards

1
Q

How to select salary and add 300?

A

select salary, firstname, salary+300 from employees;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Use aliases for select firstname and say name

A

select first_name as FirstName from Employees;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Use aliases for select firstname and say name

A

select first_name as FirstName from Employees;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Concatenate firstname and lastname and alias as full name

A

select firstname||lastname as fullname from employees;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
Get this output for me:
"Nilima is a programmer"
and nilima = firstname
job = programmer
with alias
A

select firstname ||’is a ‘|| job as employee_details from employees;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Use q operator and write down “yea”

A

select firstname|| q’{yea] || managers as “Managers” from employees;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Display all rows from employees

A

select department_id * from employees;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Display unique elements

A

select DISTINT department_id from employees;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does Describe do?

A

Displays the structure of a table

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Select from employees where last_name is nilima.

and avoid that common mistake

A

select last_name
from employees
where
last_name=”nilima”;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Select from employees where salary is less than 300, more than 300, between 200-800

A

select salary from employees
where salary BETWEEN 200 AND 800;
select salary from employees where salary <=300;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Select names that begin with like “anychari”

A

select firstname from employees where firstname like ‘_i%’;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How to find null manager id from employees?

A

select manager_id from employees where manager_id IS NULL;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

select from employees where salary is greater than 1000 and job_id is has the word “man” so IT_MAN

A

select manager_id from employees where
salary>=1000
AND
job_id LIKE ‘%MAN%’;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

select from employees where salary is greater than 1000 or job_id is has the word “man” so IT_MAN

A

select manager_id from employees where
salary>=1000
or
job_id LIKE ‘%MAN%’;

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the rule of precedence AND, OR and NOT

A

NOT
AND
OR

17
Q

how to sort in descending order

A

select firstname from employees

ORDER By date desc;

18
Q

Name function that changes to upper, lower and initcap

A

UPPER(“nilima”); NILIMA
LOWER(“manandhar”); manandhar
INITCAP(“nilima maandhar”);
Nilima Manandhar

19
Q

Use lower in sql query

A

Select last_name from employees where LOWER(first_name) = ‘manandhar’;

20
Q

How do you concat string?

A

CONCAT(‘hello’, ‘world’);

21
Q

How to find length,
I have Hello World.
I want only Hello
get rid of h from hellow

A

LENGTH(‘HELLOWORLD’);
SUBSTR(‘HELLOWORLD’, 1 ,5);
TRIM(‘H’ from ‘hellow’)

22
Q

What is the default date?

A

dd-MON-YY

23
Q

What does sysdate return?

A

it returns date and time
select sysdate
from dual;

24
Q

how to convert character, numbers and date?

A

to_char
to_date
to_number

25
Q

Name group functions

A

AVG, count, max, min, sum

26
Q

when do you use group by?

A

if you have group functions and select department_id then department_id should be group by
select avg(salary)
from employees
group by department_id;

27
Q
Can you use where like this
where AVG(salary)>300;
A

No that’s why you use having?

Having(salary)>=300;

28
Q

What is a natural join?

A

it is based on all columns in the two tables that have the same name.
It selects rows from the two tables that have equal values in all matched columns