Java Reference
In-Depth Information
7.
Perform Steps 7-9 of Section 24.5.1 to create the
addressbook
database. In each
step, replace
books
with
addressbook
.
You're now ready to execute this chapter's examples.
After setting the
JAVA_HOME
environment variable, perform the following steps:
1.
Open a shell window.
2.
Perform the steps in Section 24.5.2, but in Step 1, set
DERBY_HOME
to
DERBY_HOME=
YourLinuxJDKInstallationFolder
/db
On our Ubuntu Linux system, this was:
DERBY_HOME=/usr/lib/jvm/java-7-oracle/db
You're now ready to execute this chapter's examples.
This section presents two examples. The first introduces how to connect to a database and
query it. The second demonstrates how to display the result of the query in a
JTable
.
The example of Fig. 24.23 performs a simple query on the
books
database that retrieves
the entire
Authors
table and displays the data. The program illustrates connecting to the
database, querying the database and processing the result. The discussion that follows pres-
ents the key JDBC aspects of the program.
Lines 3-8 import the JDBC interfaces and classes from package
java.sql
used in this
program. Method
main
(lines 12-48) connects to the
books
database, queries the database,
displays the query result and closes the database connection. Line 14 declares a
String
constant for the database URL. This identifies the name of the database to connect to, as
well as information about the protocol used by the JDBC driver (discussed shortly). Lines
15-16 declare a
String
constant representing the SQL query that will select the
authorID
,
firstName
and
lastName
columns in the database's
authors
table.
1
// Fig. 24.23: DisplayAuthors.java
2
// Displaying the contents of the Authors table.
3
import
java.sql.Connection;
4
import
java.sql.Statement;
5
import
java.sql.DriverManager;
6
import
java.sql.ResultSet;
7
import
java.sql.ResultSetMetaData;
8
import
java.sql.SQLException;
9
10
public class
DisplayAuthors
11
{
Fig. 24.23
|
Displaying the contents of the
Authors
table. (Part 1 of 2.)
