8. String Functions

Question 1

Combine first_name and country of customer as:
<name> from <country>.

Answer 1

select first_name, country,
concat(first_name, ' from ', country) as combined_name
from customers;

Question 2

Find customers whose first_name has leading or trailing whitespaces.

Answer 2

select first_name
from customers
where first_name != trim(first_name);

Question 3

Remove - from a phone number.

Answer 3

select '123-456-789',
replace('123-456-789', '-', '') as new_phone

Question 4

retrieve first 2 characters from first_name of customers table.

Answer 4

select left(first_name, 2) 
from customers;

Question 5

Retrieve customers’ first names after removing the first (non-space) character.

Answer 5

select first_name,
substring(trim(first_name), 2, len(first_name)) as substr_name

Question 6

Round the number 3.516 to 2 decimal places.

Answer 6

select 3.516,
round(3.516, 2) as rounded;

3.520