Solution of the exercises of the book: "Learning SQL", 2nd Edition, O'Reilly

Query Primer: basic use of the 'SELECT', 'FROM', 'WHERE', 'GROUP BY' clause.

Filtering: understand the various type of filtering conditions that can be implemented in the 'WHERE' clauses of 'SELECT', 'UPDATE' and 'DELETE' statements.

Querying multiple tables: understan how you can join multiple tables togheter. This chapter focus is attention in the most common join, the 'INNER JOIN'

Working with sets: basic notion of set theory and how you can combine multiple tables using various set operators.

Data generation, conversion and manipulation: generation, conversion and manipulation of string, numeric and temporal data.

Grouping and aggregates: how data can be grouped and aggregated to allow users to interact with it at some higher level of granularity than what is stored in the database.

Subqueries: how to define and use subqueries. A subquery is a query contained within another SQL statment.

Joins revisited: focus on other way you can possibly join tables, including the 'OUTER JOIN' and the 'CROSS JOIN'.

Conditional logic: how to write statements that can behave differently depending on the data encounterd during statement execution.

Transactions: explore the need and the infrastructure necessary to execute multiple SQL statements concurrently.

Indexes and constraints: how to deal with database features that can indirectly affect the code.

Views: define what views are, how they are defined, and when and how you may want to use them.

Metadata: informations about all of the database objects that were created to store the data. Understand how you can access the 'metadata' and how you can use it.