Hidden SQL Facts

 Hidden SQL Facts

Here are 50 things you might not know about SQL:

1. SQL stands for Structured Query Language.
2. It was first developed by IBM in the 1970s.
3. SQL is not case-sensitive for keywords but is case-sensitive for data.
4. SQL operates on relational databases, which store data in tables.
5. There are different SQL database management systems (DBMS) like MySQL, PostgreSQL, SQLite, and Oracle.
6. SQL can be used for data manipulation (INSERT, UPDATE, DELETE) and querying (SELECT).
7. The SQL SELECT statement is used to retrieve data from a database.
8. SQL supports various types of joins: INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.
9. GROUP BY is used to aggregate data and apply functions like SUM, COUNT, AVG, etc.
10. HAVING filters results after the GROUP BY clause.
11. SQL's ORDER BY sorts query results in ascending or descending order.
12. SQL supports subqueries, allowing you to nest one query within another.
13. The UNION operator combines results from multiple SELECT statements.
14. SQL views are virtual tables that store the result of a SELECT query.
15. Transactions ensure data consistency and can be managed using BEGIN, COMMIT, and ROLLBACK.
16. ACID (Atomicity, Consistency, Isolation, Durability) properties ensure data integrity.
17. SQL injection is a security vulnerability that occurs when user input is not properly sanitized.
18. Common data types in SQL include INTEGER, VARCHAR, DATE, and BOOLEAN.
19. The ALTER TABLE statement is used to modify existing database tables.
20. INDEXES improve query performance by providing faster data retrieval.
21. Stored procedures are precompiled SQL code for specific tasks.
22. Triggers are automatic actions that respond to certain events in the database.
23. SQL supports regular expressions for advanced pattern matching.
24. The CASE statement performs conditional logic in SQL queries.
25. SQL supports scalar functions (UPPER, LOWER) and mathematical functions (ABS, ROUND).
26. Common aggregate functions include MAX, MIN, SUM, AVG, and COUNT.
27. The PRIMARY KEY uniquely identifies a row in a table.
28. FOREIGN KEY establishes relationships between tables.
29. SQL NULL represents the absence of a value.
30. The COALESCE function returns the first non-null value in a list.
31. Full-text search allows searching for text within a large body of text data.
32. SQL's MERGE statement combines INSERT, UPDATE, and DELETE operations.
33. Window functions perform calculations across a set of table rows.
34. Common window functions are ROW_NUMBER, RANK, DENSE_RANK, and LAG.
35. The OFFSET-FETCH clause is used for result pagination.
36. Common table expressions (CTEs) simplify complex queries by creating temporary result sets.
37. JSON functions allow storing, querying, and manipulating JSON data.
38. Temporal tables store historical data, allowing you to track changes over time.
39. SQL Workbench is a popular open-source SQL client tool.
40. SQL Server Management Studio (SSMS) is a Microsoft tool for SQL Server.
41. pgAdmin is a widely used open-source administration and management tool for PostgreSQL.
42. SQL transactions can be managed using the COMMIT and ROLLBACK statements.
43. The EXISTS operator checks for the existence of rows in a subquery.
44. The ROW_NUMBER() function assigns a unique number to each row in a result set.
45. Common table expressions (CTEs) improve query readability and reusability.
46. The LIKE operator and wildcard characters allow pattern matching in queries.
47. SQL's TRUNCATE statement removes all rows from a table without logging individual deletions.
48. The CASE statement can perform conditional updates and inserts.
49. The COALESCE function is used to return the first non-null value in a list of expressions.
50. SQL is used not only in databases but also in data warehousing and data analytics platforms.
51. Feel free to ask if you'd like more details on any of these points!