What Is Structured Query Language (SQL)?

Structured Query Language (SQL) is the most widely implemented database query language and is supported by many popular relational database systems, including: MS SQL Server, IBM DB2, MySQL, and Microsoft Access.

Since the late 1980s, SQL (pronounced ‘S Q L’ or ‘sequel’) has been a standard for both the International Organization for Standardization (ISO) and the American National Standards Institute (ANSI). Although SQL is considered a standard, database technology providers usually have their own SQL editor and there can be small variations in the syntax depending on how the SQL features are implemented.

SQLite3 implements a database engine and understands most of the standard SQL language. You can also check out the following pages for more information:

• SQLite3
• SQL as understood by SQLite
• Quirks, caveats, and gotchas in SQLite

To help you learn SQL, we’ll present snippets of SQL. You’ll generally see examples of SQL presented like this:

CREATE TABLE Customers (
 CustomerID integer PRIMARY KEY AUTOINCREMENT,
 LastName varchar(255),
 FirstName varchar(255),
 DOB varchar(255),
 Mobile integer,
 CountryCode char(4) 
);

We’ll also show the output of any SQL or SQLite commands as follows

sqlite> SELECT * FROM Artist;
ArtistId Name 
---------- ----------
1 AC/DC 
2 Accept 
3 Aerosmith 
...