Project: Analyzing Students' Mental Health in 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)

DataFrameas

students

variable

-- Run this code to save the CSV file as students
SELECT * 
FROM 'students.csv';

DataFrameas

df

variable

-- Start coding here...
SELECT COUNT(*) as total_records 
FROM students;

SELECT COUNT(inter_dom) as count_inter_dom
FROM students;

--Code for filtering data
SELECT *
FROM students
WHERE inter_dom = 'Inter';
SELECT *
FROM students
WHERE inter_dom = 'Dom';
SELECT * 
FROM students
WHERE inter_dom IS NULL;

--Code for aggregate functions
SELECT ROUND(MIN(todep), 2) as min_phq, ROUND(MAX(todep),2) as max_phq, ROUND(AVG(todep),2) as avg_phq, 
       ROUND(MIN(tosc), 2) as min_scs, ROUND(MAX(tosc),2) as max_scs, ROUND(AVG(tosc),2) as avg_scs, 
       ROUND(MIN(toas), 2) as min_as, ROUND(MAX(toas),2) as max_as, ROUND(AVG(toas),2) as avg_as
FROM students
GROUP BY inter_dom;

--Code for final result
SELECT stay, avg_phq as average_phq, avg_scs as average_scs, avg_as as average_as
FROM (
    SELECT stay, ROUND(AVG(todep), 2) as avg_phq, ROUND(AVG(tosc), 2) as avg_scs, ROUND(AVG(toas), 2) as avg_as
    FROM students
    WHERE inter_dom = 'Inter'
    GROUP BY stay
) as df
ORDER BY stay DESC;