Absolute Beginner’s Guide to Databases

What You Have Learned

This chapter has provided you with a quick overview of what SQL is and how one of the most used parts of the language, the Select command, is used. You have learned how to use the SQL Select command to extract data from tables in a database. The From clause specifies the primary table used to support the query. The Where clause provides a mechanism for filtering data in the resultset. Top n Queries and the Distinct clause are other tools for limiting the data returned to the resultset. The Join clause allows you to extract data from multiple tables. In addition to these features, you also learned how to use the Union clause to combine data from multiple queries into a single resultset. In addition, you learned the As clause ...