As we have said, Microsoft Access uses a form of query language referred to as Structured Query Language, or SQL. (I prefer to pronounce SQL by saying each letter separately, rather than saying “sequel.” Accordingly, I will write “an SQL statement” rather than “a SQL statement.”)
SQL is the most common database query language in use today. It is actually more than just a query language, as I have defined the term in the previous chapter. It is a complete database management system (DBMS) language, in that it has the capability not only to manipulate the components of a database, but also to create them in the first place. In particular, SQL has the following components:
A data definition language (DDL)component, to allow the definition (creation) of database components, such as tables.
A data manipulation language (DML) component, to allow manipulation of database components.
A data control language (DCL) component, to provide internal security for a database.
We will discuss the first two components of SQL in some detail in this chapter.
SQL (also known as SEQUEL) was developed by IBM in San Jose, California. The current version of SQL is called SQL-92. However, Microsoft Access, like all other commercial products that support SQL, does not implement the complete SQL-92 standard and in fact adds some additional features of its own to the language. Since this book uses Microsoft Access, we will discuss the Access ...