Please note that the following blog post provides a summary view for what you need to get done (left column) and quick examples that illustrate how to do it in SQL (right column with SQL code in red). For more information please see the resources below:
- SQL Course 2. (2018). SQL Course 2: Interactive Online SQL Training. Retrieved from http://www.sqlcourse2.com/
- Mode Community. (2018). The SQL Tutorial for Data Analysis. Retrieved from https://community.modeanalytics.com/sql/tutorial/introduction-to-sql/
- Programmer Interview. (2018). Practice SQL Interview Questions and Answers. Retrieved from http://www.programmerinterview.com/index.php/database-sql/practice-interview-question-1/
| AVG, COUNT, MAX, MIN, STDDEV, SUM, VARIANCE |
SELECT AVG(sal), MAX(sal), MIN(sal), SUM(sal) FROM emp WHERE jobs LIKE ‘Sales%’ |
| COUNT |
SELECT COUNT(*) FROM emp WHERE deptno = 30 |
| Group By |
SELECT deptno, AVG(sal) FROM emp GROUP BY deptno |
| Rollup and cube |
SELECT deptno, MAX(sal) FROM emp GROUP BY deptno WITH ROLLUP [CUBE] |
| Having |
SELECT deptno, MAX(sal) FROM emp GROUP BY deptno HAVING max(sal)>2900 |
Dr. Skylar (Sky) Hernandez 