#freelancer • 1y
Here are some essential SQL topics for data analysts: 1. Basic Queries: SELECT, FROM, WHERE clauses. 2. Sorting and Filtering: ORDER BY, GROUP BY, HAVING. 3. Joins: INNER JOIN, LEFT JOIN, RIGHT JOIN. 4. Aggregation Functions: COUNT, SUM, AVG, MIN, MAX. 5. Subqueries: Embedding queries within queries. 6. Data Modification: INSERT, UPDATE, DELETE. 7. Indexes: Optimizing query performance. 8. Normalization: Efficient database design. 9. Views: Creating virtual tables for simplified queries. 10. Database Relationships: One-to-One, One-to-Many, Many-to-Many. Window functions are also important: - ROW_NUMBER(): Assigns a unique number to each row. - RANK() and DENSE_RANK(): Rank data with ties handling. - LAG() and LEAD(): Access data from preceding or following rows. - SUM(), AVG(), MIN(), MAX(): Aggregations over a defined window.
Every Dream is Worth... • 5m
Founder: The app is slow. Can we just increase the server size? Backend Dev: So you want to pay more instead of fixing the problem? Founder: ...What's the problem? Backend Dev: Too many database queries, no caching, and inefficient API calls. Fo
See MoreFull Stack Web Devel... • 8m
Security testing ensures that applications are free from vulnerabilities like SQL Injection, XSS, CSRF, and IDOR. SQL Injection occurs when unsanitized inputs allow attackers to manipulate database queries. This can be mitigated by using parameterize
See MoreKeen Learner and Exp... • 16d
Day 28 of learning python as a beginner. Topic: web scraping with postgreSQL database. When I posted my first web scraping project I just had the result on console however I wanted it to be stored somewhere where it can be reviewed later that's whe
See MoreBuilding an AI eco-s... • 5m
I feel pride in announcing our Made in India, Real-Time Vector Database - SwarnDB. SwarnDB is a SarthiAI initiative towards an effort to create an end to end eco-system for the future of AI. We tested SwarnDB with 100K vector records of 1536 dime
See MoreDownload the medial app to read full posts, comements and news.