✰ Throughout these SQL Projects we've covered a wide variety of methods for transforming, manipulating, and calculating data to answer a wide variety of questions in SQL:

• We used CASE Statements for categorizing, aggregating and calculating information.
• We used subqueries in FROM Clause.
• We joined multiple tables.
• We used nested and correlated subqueries to extract, match, and organize large amounts of data.
• We used Aggregation, ORDER BY, GROUB BY, WHERE and HAVING Clauses to filter and manipulate the Data.

✰ 2019 Database Trends – SQL vs. NoSQL, Top Databases, Single vs. Multiple Database Use:

✰ System Properties Comparison between: Microsoft SQL Server, MongoDB, MySQL, Oracle and PostgreSQL.