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Introduction to SQLite

This is SQLite tutorial. It covers the SQLite database engine, sqlite3 command line tool and the SQL language covered by the database engine. It is an introductory tutorial for the beginners. It covers SQLite version 3.0.

SQLite database

SQLite is an embedded relational database engine. Its developers call it a self-contained, serverless, zero-configuration and transactional SQL database engine. It is very popular and there are hundreds of millions copies worldwide in use today. SQLite is used in the Solaris 10 and Mac OS operating systems and by iPhone and Skype. The Qt4 library has built-in support for SQLite as well as the Python and PHP languages. Many popular applications use SQLite internally such as Firefox, Google Chrome or Amarok.

SQLite implements most of the SQL-92 standard for SQL. The SQLite engine is not a standalone process. Instead, it is statically or dynamically linked into the application. The SQLite library is small. It can require less than 300 KiB. An SQLite database is a single ordinary disk file that can be located anywhere in the directory hierarchy. It is a cross platform file. It can be used on various operating systems, both 32 and 64 bit architectures. SQLite was written in the C programming language. It has bindings for many languages, including C++, Java, C#, Python, Perl, Ruby, Visual Basic, and Tcl. The source code of SQLite is in public domain.

Definitions

A relational database is a collection of data organized in tables. There are relations among the tables. The tables are formally described. They consist of rows and columns. SQL (Structured Query Language) is a database computer language designed for managing data in relational database management systems. A table is a set of values that is organized using a model of vertical columns and horizontal rows. The columns are identified by their names. A schema of a database system is its structure described in a formal language. It defines the tables, the fields, relationships, views, indexes, procedures, functions, queues, triggers and other elements. A database row represents a single, implicitly structured data item in a table. It is also called a tuple or a record. A column is a set of data values of a particular simple type, one for each row of the table. The columns provide the structure according to which the rows are composed. A field is a single item that exists at the intersection between one row and one column. A primary key uniquely identifies each record in the table. A foreign key is a referential constraint between two tables. The foreign key identifies a column or a set of columns in one (referencing) table that refers to a column or set of columns in another (referenced) table. A trigger is a procedural code that is automatically executed in response to certain events on a particular table in a database. A view is a specific look on data in from one or more tables. It can arrange data in some specific order, highlight or hide some data. A view consists of a stored query accessible as a virtual table composed of the result set of a query. Unlike ordinary tables a view does not form part of the physical schema. It is a dynamic, virtual table computed or collated from data in the database. A transaction is an atomic unit of database operations against the data in one or more databases. The effects of all the SQL statements in a transaction can be either all committed to the database or all rolled back. An SQL result set is a set of rows from a database returned by the SELECT statement. It also contains meta-information about the query such as the column names and the types and sizes of each column. An index is a data structure that improves the speed of data retrieval operations on a database table.

Tables used

Here we will list all the tables that are used throughout the tutorial. The .read command of the sqlite3 tool is used to execute the SQL statements from the file.

sqlite> .read authors.sql

Here we execute the SQL statements located in the authors.sql file.

Movies database

This is the movies.db database. There are three tables: Actors, Movies and ActorsMovies.

-- SQL for the Actors table

BEGIN TRANSACTION;
CREATE TABLE Actors(AId integer primary key autoincrement, Name text);
INSERT INTO Actors VALUES(1,'Philip Seymour Hofman');
INSERT INTO Actors VALUES(2,'Kate Shindle');
INSERT INTO Actors VALUES(3,'Kelci Stephenson');
INSERT INTO Actors VALUES(4,'Al Pacino');
INSERT INTO Actors VALUES(5,'Gabrielle Anwar');
INSERT INTO Actors VALUES(6,'Patricia Arquette');
INSERT INTO Actors VALUES(7,'Gabriel Byrne');
INSERT INTO Actors VALUES(8,'Max von Sydow');
INSERT INTO Actors VALUES(9,'Ellen Burstyn');
INSERT INTO Actors VALUES(10,'Jason Miller');
COMMIT;

This is the Actors table.

-- SQL for the Movies table

BEGIN TRANSACTION;
CREATE TABLE Movies(MId integer primary key autoincrement, Title text);
INSERT INTO Movies VALUES(1,'Capote');
INSERT INTO Movies VALUES(2,'Scent of a woman');
INSERT INTO Movies VALUES(3,'Stigmata');
INSERT INTO Movies VALUES(4,'Exorcist');
INSERT INTO Movies VALUES(5,'Hamsun');
COMMIT;

This is the Movies table.

-- SQL for the ActorsMovies table

BEGIN TRANSACTION;
CREATE TABLE ActorsMovies(Id integer primary key autoincrement, 
                          AId integer, MId integer);
INSERT INTO ActorsMovies VALUES(1,1,1);
INSERT INTO ActorsMovies VALUES(2,2,1);
INSERT INTO ActorsMovies VALUES(3,3,1);
INSERT INTO ActorsMovies VALUES(4,4,2);
INSERT INTO ActorsMovies VALUES(5,5,2);
INSERT INTO ActorsMovies VALUES(6,6,3);
INSERT INTO ActorsMovies VALUES(7,7,3);
INSERT INTO ActorsMovies VALUES(8,8,4);
INSERT INTO ActorsMovies VALUES(9,9,4);
INSERT INTO ActorsMovies VALUES(10,10,4);
INSERT INTO ActorsMovies VALUES(11,8,5);
COMMIT;

This is the ActorsMovies table.

Test database

Here we have the tables from the test.db.

-- SQL for the Cars table

BEGIN TRANSACTION;
CREATE TABLE Cars(Id integer PRIMARY KEY, Name text, Cost integer);
INSERT INTO Cars VALUES(1,'Audi',52642);
INSERT INTO Cars VALUES(2,'Mercedes',57127);
INSERT INTO Cars VALUES(3,'Skoda',9000);
INSERT INTO Cars VALUES(4,'Volvo',29000);
INSERT INTO Cars VALUES(5,'Bentley',350000);
INSERT INTO Cars VALUES(6,'Citroen',21000);
INSERT INTO Cars VALUES(7,'Hummer',41400);
INSERT INTO Cars VALUES(8,'Volkswagen',21600);
COMMIT;

This is the Cars table.

-- SQL for the orders table

BEGIN TRANSACTION;
CREATE TABLE Orders(Id integer PRIMARY KEY, OrderPrice integer CHECK(OrderPrice>0), 
                    Customer text);
INSERT INTO Orders(OrderPrice, Customer) VALUES(1200, "Williamson");
INSERT INTO Orders(OrderPrice, Customer) VALUES(200, "Robertson");
INSERT INTO Orders(OrderPrice, Customer) VALUES(40, "Robertson");
INSERT INTO Orders(OrderPrice, Customer) VALUES(1640, "Smith");
INSERT INTO Orders(OrderPrice, Customer) VALUES(100, "Robertson");
INSERT INTO Orders(OrderPrice, Customer) VALUES(50, "Williamson");
INSERT INTO Orders(OrderPrice, Customer) VALUES(150, "Smith");
INSERT INTO Orders(OrderPrice, Customer) VALUES(250, "Smith");
INSERT INTO Orders(OrderPrice, Customer) VALUES(840, "Brown");
INSERT INTO Orders(OrderPrice, Customer) VALUES(440, "Black");
INSERT INTO Orders(OrderPrice, Customer) VALUES(20, "Brown");
COMMIT;

This is the Orders table.

-- SQL for the Friends table

BEGIN TRANSACTION;
CREATE TABLE Friends(Id integer PRIMARY KEY, Name text UNIQUE NOT NULL, 
                     Sex text CHECK(Sex IN ('M', 'F')));
INSERT INTO Friends VALUES(1,'Jane', 'F');
INSERT INTO Friends VALUES(2,'Thomas', 'M');
INSERT INTO Friends VALUES(3,'Franklin', 'M');
INSERT INTO Friends VALUES(4,'Elisabeth', 'F');
INSERT INTO Friends VALUES(5,'Mary', 'F');
INSERT INTO Friends VALUES(6,'Lucy', 'F');
INSERT INTO Friends VALUES(7,'Jack', 'M');
COMMIT;

This is the Friends table.

-- SQL for the Customers, Reservations tables

BEGIN TRANSACTION;
CREATE TABLE IF NOT EXISTS Customers(CustomerId integer PRIMARY KEY, Name text);
INSERT INTO Customers(Name) VALUES('Paul Novak');
INSERT INTO Customers(Name) VALUES('Terry Neils');
INSERT INTO Customers(Name) VALUES('Jack Fonda');
INSERT INTO Customers(Name) VALUES('Tom Willis');

CREATE TABLE IF NOT EXISTS Reservations(Id integer PRIMARY KEY, 
                                        CustomerId integer, Day text);
INSERT INTO Reservations(CustomerId, Day) VALUES(1, '2009-22-11');
INSERT INTO Reservations(CustomerId, Day) VALUES(2, '2009-28-11');
INSERT INTO Reservations(CustomerId, Day) VALUES(2, '2009-29-11');
INSERT INTO Reservations(CustomerId, Day) VALUES(1, '2009-29-11');
INSERT INTO Reservations(CustomerId, Day) VALUES(3, '2009-02-12');
COMMIT;

This are the Customers and Reservations tables.

-- SQL for the Books table

BEGIN TRANSACTION;
CREATE TABLE Books(Id integer PRIMARY KEY, Title text, Author text, 
                   Isbn text default 'not available');
INSERT INTO Books VALUES(1,'War and Peace','Leo Tolstoy','978-0345472403');
INSERT INTO Books VALUES(2,'The Brothers Karamazov',
                         'Fyodor Dostoyevsky','978-0486437910');
INSERT INTO Books VALUES(3,'Crime and Punishment',
                         'Fyodor Dostoyevsky','978-1840224306');
COMMIT;

This is the Books table.

Sources

This chapter was an introduction to the SQLite database.