Project_Student-mental-health-analysis.sql

# 
/*
Does going to university in a different country affect your mental health?
A Japanese international university surveyed its students in 2018 and published a study the
following year that was approved by several ethical and regulatory boards.

The study found that international students have a higher risk of mental health difficulties
than the general population, and that social connectedness (belonging to a social group) and
acculturative stress (stress associated with joining a new culture) are predictive of depression.

Explore the students data using PostgreSQL to find out if you would come to a similar
conclusion for international students and see if the length of stay is a contributing factor.
*/

/*
Here is a data description of the columns you may find helpful.

Field Name			Description

inter_dom		Types of students (international or domestic)
japanese_cate	Japanese language proficiency
english_cate	English language proficiency
academic		Current academic level (undergraduate or graduate)
age				Current age of student
stay			Current length of stay in years
todep			Total score of depression (PHQ-9 test)
tosc			Total score of social connectedness (SCS test)
toas			Total score of acculturative stress (ASISS test)
*/

-- Find the number of international students and their average scores by length of stay, in descending order of length of stay
SELECT stay, 
       COUNT(*) AS count_int,
       ROUND(AVG(todep), 2) AS average_phq, 
       ROUND(AVG(tosc), 2) AS average_scs, 
       ROUND(AVG(toas), 2) AS average_as
FROM students
WHERE inter_dom = 'Inter'
GROUP BY stay
ORDER BY stay DESC;