SQL Exercise 6:CONCAT

Generate the following two result sets:

1. Query an alphabetically ordered list of all names in OCCUPATIONS, immediately followed by the first letter of each profession as a parenthetical (i.e.: enclosed in parentheses). For example: AnActorName(A), ADoctorName(D), AProfessorName(P), and ASingerName(S).
2. Query the number of ocurrences of each occupation in OCCUPATIONS. Sort the occurrences in ascending order, and output them in the following format:

    There are a total of [occupation_count] [occupation]s.
   

   where [occupation_count] is the number of occurrences of an occupation in OCCUPATIONS and [occupation] is the lowercase occupation name. If more than one Occupation has the same [occupation_count], they should be ordered alphabetically. Note: There will be at least two entries in the table for each type of occupation.

   Input Format

The OCCUPATIONS table is described as follows:

Filed	Type
NAME	STRING
OCCUPATION	STRING

Occupation will only contain one of the following values: Doctor, Professor, Singer or Actor.

Analysis

1. Use CONCAT() to combine the string we want.

    Syntax
    CONCAT(expression1, expression2, expression3,...)
   

2. To get the abbreviation of occupation, we can use the SUBSTR() function.

   Syntax
   SUBSTR(string, start, length)
   # In this case
   # SUBSTR(OCCUPATION, 1, 1)
   

3. sort the result with ORDER BY keyword.
4. Do the same things in second query.

ANS

#

SELECT CONCAT(NAME,'(',SUBSTR(OCCUPATION,1,1),')')
FROM OCCUPATIONS
ORDER BY NAME;

SELECT CONCAT('There are a total of ',COUNT(OCCUPATION),' ',LOWER(OCCUPATION),'s.')
FROM OCCUPATIONS
GROUP BY OCCUPATION
ORDER BY COUNT(OCCUPATION),OCCUPATION;

Expected Output

Aamina(D) 
Ashley(P) 
Belvet(P) 
Britney(P) 
Christeen(S) 
Eve(A) 
Jane(S) 
Jennifer(A) 
Jenny(S) 
Julia(D) 
Ketty(A) 
Kristeen(S) 
Maria(P) 
Meera(P) 
Naomi(P) 
Priya(D) 
Priyanka(P) 
Samantha(A) 
There are a total of 3 doctors. 
There are a total of 4 actors. 
There are a total of 4 singers. 
There are a total of 7 professors.