Course tips and study guides
Study plans, exam and interview preparation, projects and placements, from people a year or two ahead and the UniCircle team. Every tip names its author and is checked by an editor before it appears.
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5 tips tagged #sql
- GuideEngineeringUndergraduateWindow functions for interviews: ROW_NUMBER, RANK and running totalsThe three window-function patterns that solve most 'top N per group' and 'running total' questions in SQL interviews, with the difference between RANK and DENSE_RANK.#sql#window functions#rank#interviewUniCircle team2 min
- GuideEngineeringUndergraduateSQL joins explained with two small tablesInner, left, right, full and self joins shown on the same two tiny tables, so you can see exactly which rows each one keeps.#sql#joins#left join#self joinUniCircle team2 min
- GuideEngineeringUndergraduateGROUP BY and HAVING without the confusionWhat GROUP BY actually does to your rows, why WHERE and HAVING are different, and the one rule about which columns you may select.#sql#group by#having#aggregatesUniCircle team2 min
- GuideEngineeringUndergraduateSQL filters and sorting: WHERE, IN, BETWEEN, LIKE and NULLHow to pick exactly the rows you want in SQL, including the NULL trap that catches most students, and how ORDER BY and LIMIT work together.#sql#where#null#order byUniCircle team2 min
- GuideEngineeringUndergraduatePostgreSQL commands you will use in your first weekThe psql shortcuts and SQL statements that cover almost everything a student does in a first DBMS lab: connect, look around, create a table, add rows, change them and clean up.#postgresql#sql#psql#dbms labUniCircle team2 min
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