Set operators: UNION, INTERSECT, and EXCEPT, help combine or compare query results. Example: This merges patients from both lists. 💡 Future clinical idea: Use INTERSECT to identify patients who are both in a high-risk med list and have a recent adverse event record.
Tag: Clinical Data
SQL Joins Advanced
Beyond INNER JOIN, SQL also has LEFT, RIGHT, and FULL joins. These can bring in unmatched rows, letting you see what’s missing. LEFT JOIN retrieves all records from the left table and the matched records from the right table, while RIGHT JOIN does the opposite, fetching all records from the right table along with matched…
SQL Joins Basics
The INNER JOIN lets you combine related data from multiple tables. It’s a core SQL concept for connecting information. By using INNER JOIN, you ensure that only the records with matching values in both tables are retrieved, which helps maintain data integrity and relevance. For those looking to deepen their understanding of database interactions, sql…
Filtering Data in SQL
One of the first essential skills in SQL is filtering data with the WHERE clause. It’s how you narrow your results to exactly what you need. Example: This query shows only patients older than 65. In the future, I could use this approach to quickly find all geriatric patients on a high-risk medication to support…