Have you worked with SQL? At what level?

Yes, I have worked with SQL at a level sufficient for analyzing and optimizing queries, creating complex selections, and working with databases within projects.

My skills include:

• Writing SELECT queries with JOIN, GROUP BY, HAVING
• Creating and modifying tables (DDL)
• Using subqueries and window functions
• Optimizing queries using indexes and execution plan analysis
• Working with transactions and data integrity management

For example, I have written queries to fetch data with multiple conditions and table joins, which allowed generating necessary reports for business analysis.