Sams Teach Yourself SQL in 21 Days, Fourth Edition

Week 2: At a Glance

Week 1 covers the basic SQL query using the SELECT statement. Beginning with the simplest SELECT statement, you learned how to retrieve data from a database. Then you moved on to the SQL functions, which are useful in converting to money or date formats, for example. You quickly learned that you can retrieve data from a database in many ways. Clauses such as WHERE, ORDER BY, and GROUP BY enable you to tailor a query to return a specific set of records. You can use a join to return a set of data from a group of tables. Subqueries are especially useful when you need to execute several queries, each of which depends on data returned from an earlier query.

Week 2 moves on to some more advanced uses of SQL:

• Day 8 covers database ...