CIS 270—Application Development II Chapter 25—Accessing Databases with JDBC

Introduction A _________ is an organized collection of data. A database management system (DBMS) is software that stores and organizes data in a special format. The most popular type of database is a relational database where data are stored in related _______. Popular relational database management systems (RDBMSs) include Access, Oracle, DB2, and MySQL. SQL (structured ______ language) is the standard RDBMS language for manipulating data. Java communicates with RDBMSs using the ____ API and drivers that implement it to a given database.

Relational Databases A relational database is a logical representation of data that allows data access w/o consideration of the __________ structure of the data. Data are stored in tables. The table represents a particular entity (Employee). Columns represent the _________ of an entity (ssn). A ________ represents a specific instance of an entity (employee John Doe). A primary ___ for a table is a column (field), or group of columns, that uniquely identifies a row (record). A ________ key is a column in one table that is a primary key in another related table.

The books Database Four tables: authors authorID, firstName, lastName publishers publisherID, publisherName titles isbn, title, editionNumber, copyright, publisherID, imageFile, price authorISBN authorID, isbn ______-relationship diagram ERD authors authorID firstName lastName authorISBN authorID isbn titles isbn title editionNumber copyright publisherID imageFile price publishers publisherID publisherName 1 n n 1

SELECT SELECT * FROM titles (select all _______ from titles) SELECT isbn, title, price FROM titles (only certain columns) SELECT * FROM titles WHERE copyright > 2000 (only certain ______) SELECT * FROM authors WHERE lastname LIKE ‘D%’ (last name starts with D) SELECT * FROM authors ORDER BY lastName, firstName (sort ___________ by default) SELECT isbn, title, price FROM titles WHERE price < 20 ORDER BY price DESC

INNER JOIN SELECT firstName, lastName, isbn FROM authors INNER JOIN authorISBN ON authors.authorID = authorISBN.authorID ORDER BY lastName, firstName This SQL statement lists the authors with their ISBNs SELECT determines the __________ FROM and INNER JOIN determines the two _______ ON specifies the common columns ORDER BY specifies sorting

INSERT, UPDATE, DELETE Insert a row in a table INSERT INTO authors (firstName, lastName) VALUES ( ‘Sue’, ‘Smith’ ) Update a row in a table UPDATE authors SET lastName = ‘Jones’ WHERE lastName = ‘Smith’ AND firstName = ‘Sue’ Delete a row in a table DELETE FROM authors WHERE authorID = 5

8 Using JDBC The four basic steps involved with using JDBC to connect to a database are: Load the appropriate JDBC driver Request a connection to the database Send SQL to the database Process results, if appropriate See /21/jdbc.html for more information. /21/jdbc.html

9 DisplayAuthors.java I Import package sql import java.sql.*; Identify driver class JdbcOdbcDriver static final String JDBC_DRIVER = "sun.jdbc.odbc.JdbcOdbcDriver"; Identify database file (books.mdb) static final String DATABASE_URL = “jdbc:odbc:books”; “jdbc:odbc:books” contains the communication ___________ ( jdbc ), subprotocol ( odbc ), and database name ( books )

10 DisplayAuthors.java II Create a Connection object to connect the Java program to the ___________ private Connection connection = DriverManager.getConnection( DATABASE_URL ); Set the location of the database with the property name and value System.setProperty( “odbc.system.home”, “C:/” );

11 DisplayAuthors.java III Get the specified Class object ( JdbcOdbcDriver ) Class.forName( JDBC_DRIVER ); Create a Statement object for submitting _______ statements to the database private Statement statement = connection.createStatement(); Execute an SQL statement and store results in a ResultSet object. ResultSet resultSet = statement.executeQuery( “SELECT * FROM authors” );

12 Setting Up ODBC Data Sources Open Microsoft Windows Control Panel. Double-click the Administrative Tools icon. Double-click on the Data Sources (ODBC) icon. Select the User DSN tab. To define a new data source for a currently installed driver, click Add. Complete the dialog boxes. Select Microsoft Access Driver, Finish Enter a Data Source Name (such as “books”) Click Select… and select the database, click OK