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>PostgreSQL 7.3.2 Documentation</TH
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><DIV
CLASS="CHAPTER"
><H1
><A
NAME="JDBC"
>Chapter 5. <SPAN
CLASS="ACRONYM"
>JDBC</SPAN
> Interface</A
></H1
><DIV
CLASS="TOC"
><DL
><DT
><B
>Table of Contents</B
></DT
><DT
>5.1. <A
HREF="jdbc.html#JDBC-SETUP"
>Setting up the <SPAN
CLASS="ACRONYM"
>JDBC</SPAN
> Driver</A
></DT
><DD
><DL
><DT
>5.1.1. <A
HREF="jdbc.html#JDBC-BUILD"
>Getting the Driver</A
></DT
><DT
>5.1.2. <A
HREF="jdbc.html#JDBC-CLASSPATH"
>Setting up the Class Path</A
></DT
><DT
>5.1.3. <A
HREF="jdbc.html#JDBC-PREPARE"
>Preparing the Database for <SPAN
CLASS="ACRONYM"
>JDBC</SPAN
></A
></DT
></DL
></DD
><DT
>5.2. <A
HREF="jdbc-use.html"
>Using the Driver</A
></DT
><DD
><DL
><DT
>5.2.1. <A
HREF="jdbc-use.html#JDBC-IMPORT"
>Importing <SPAN
CLASS="ACRONYM"
>JDBC</SPAN
></A
></DT
><DT
>5.2.2. <A
HREF="jdbc-use.html#JDBC-LOAD"
>Loading the Driver</A
></DT
><DT
>5.2.3. <A
HREF="jdbc-use.html#JDBC-CONNECT"
>Connecting to the Database</A
></DT
><DT
>5.2.4. <A
HREF="jdbc-use.html#JDBC-DISCONNECT"
>Closing the Connection</A
></DT
></DL
></DD
><DT
>5.3. <A
HREF="jdbc-query.html"
>Issuing a Query and Processing the Result</A
></DT
><DD
><DL
><DT
>5.3.1. <A
HREF="jdbc-query.html#AEN28179"
>Using the <TT
CLASS="CLASSNAME"
>Statement</TT
> or <TT
CLASS="CLASSNAME"
> PreparedStatement</TT
> Interface</A
></DT
><DT
>5.3.2. <A
HREF="jdbc-query.html#AEN28205"
>Using the <TT
CLASS="CLASSNAME"
>ResultSet</TT
> Interface</A
></DT
></DL
></DD
><DT
>5.4. <A
HREF="jdbc-update.html"
>Performing Updates</A
></DT
><DT
>5.5. <A
HREF="jdbc-ddl.html"
>Creating and Modifying Database Objects</A
></DT
><DT
>5.6. <A
HREF="jdbc-binary-data.html"
>Storing Binary Data</A
></DT
><DT
>5.7. <A
HREF="jdbc-ext.html"
><SPAN
CLASS="APPLICATION"
>PostgreSQL</SPAN
> Extensions to the
<SPAN
CLASS="ACRONYM"
>JDBC</SPAN
> <SPAN
CLASS="ACRONYM"
>API</SPAN
></A
></DT
><DD
><DL
><DT
>5.7.1. <A
HREF="jdbc-ext.html#AEN28340"
>Accessing the Extensions</A
></DT
><DT
>5.7.2. <A
HREF="jdbc-ext.html#AEN28586"
>Geometric Data Types</A
></DT
><DT
>5.7.3. <A
HREF="jdbc-ext.html#AEN28615"
>Large Objects</A
></DT
></DL
></DD
><DT
>5.8. <A
HREF="jdbc-thread.html"
>Using the driver in a multithreaded or a servlet environment</A
></DT
><DT
>5.9. <A
HREF="jdbc-datasource.html"
>Connection Pools And DataSources</A
></DT
><DD
><DL
><DT
>5.9.1. <A
HREF="jdbc-datasource.html#JDBC-DS-VERSION"
>JDBC, JDK Version Support</A
></DT
><DT
>5.9.2. <A
HREF="jdbc-datasource.html#JDBC-DS-INTRO"
>JDBC Connection Pooling API</A
></DT
><DT
>5.9.3. <A
HREF="jdbc-datasource.html#JDBC-DS-CPDS"
>Application Servers: ConnectionPoolDataSource</A
></DT
><DT
>5.9.4. <A
HREF="jdbc-datasource.html#JDBC-DS-DS"
>Applications: DataSource</A
></DT
><DT
>5.9.5. <A
HREF="jdbc-datasource.html#JDBC-JNDI"
>DataSources and <SPAN
CLASS="ACRONYM"
>JNDI</SPAN
></A
></DT
><DT
>5.9.6. <A
HREF="jdbc-datasource.html#JDBC-APP-SERVERS"
>Specific Application Server Configurations</A
></DT
></DL
></DD
><DT
>5.10. <A
HREF="jdbc-reading.html"
>Further Reading</A
></DT
></DL
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Author: </B
> Originally written by Peter T. Mount (<TT
CLASS="EMAIL"
><<A
HREF="mailto:peter@retep.org.uk"
>peter@retep.org.uk</A
>></TT
>),
the original author of the <SPAN
CLASS="ACRONYM"
>JDBC</SPAN
> driver.
</P
></BLOCKQUOTE
></DIV
><P
> <SPAN
CLASS="ACRONYM"
>JDBC</SPAN
> is a core <SPAN
CLASS="ACRONYM"
>API</SPAN
> of Java 1.1 and later.
It provides a standard set of
interfaces to <SPAN
CLASS="ACRONYM"
>SQL</SPAN
>-compliant databases.
</P
><P
> <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> provides a <I
CLASS="FIRSTTERM"
>type
4</I
> <SPAN
CLASS="ACRONYM"
>JDBC</SPAN
> Driver. Type 4 indicates
that the driver is written in Pure Java, and communicates in the
database system's own network protocol. Because of this, the driver
is platform independent; once compiled, the driver can be used on
any system.
</P
><P
> This chapter is not intended as a complete guide to
<SPAN
CLASS="ACRONYM"
>JDBC</SPAN
> programming, but should help to get you
started. For more information refer to the standard
<SPAN
CLASS="ACRONYM"
>JDBC</SPAN
> <SPAN
CLASS="ACRONYM"
>API</SPAN
> documentation.
Also, take a look at the examples included with the source. The
basic example is used here.
</P
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="JDBC-SETUP"
>5.1. Setting up the <SPAN
CLASS="ACRONYM"
>JDBC</SPAN
> Driver</A
></H1
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="JDBC-BUILD"
>5.1.1. Getting the Driver</A
></H2
><P
> Precompiled versions of the driver can be downloaded from
the <A
HREF="http://jdbc.postgresql.org"
TARGET="_top"
><SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
<SPAN
CLASS="ACRONYM"
>JDBC</SPAN
> web site</A
>.
</P
><P
> Alternatively you can build the driver from source, but you
should only need to do this if you are making changes to the
source code. For details, refer to the PostgreSQL installation
instructions. After installation, the driver should be found in
<TT
CLASS="FILENAME"
><TT
CLASS="REPLACEABLE"
><I
>PREFIX</I
></TT
>/share/java/postgresql.jar</TT
>.
The resulting driver will be built for the version of Java you are
running. If you build with a 1.1 <SPAN
CLASS="ACRONYM"
>JDK</SPAN
> you will build a version
that supports the JDBC 1 specification, if you build with a Java 2
<SPAN
CLASS="ACRONYM"
>JDK</SPAN
> (e.g., <SPAN
CLASS="ACRONYM"
>JDK</SPAN
> 1.2 or <SPAN
CLASS="ACRONYM"
>JDK</SPAN
> 1.3) you will build a version that
supports the JDBC 2 specification.
</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="JDBC-CLASSPATH"
>5.1.2. Setting up the Class Path</A
></H2
><P
> To use the driver, the JAR archive (named
<TT
CLASS="FILENAME"
>postgresql.jar</TT
> if you built from source, otherwise
it will likely be named <TT
CLASS="FILENAME"
>jdbc7.2-1.1.jar</TT
> or
<TT
CLASS="FILENAME"
>jdbc7.2-1.2.jar</TT
> for the JDBC 1 and JDBC 2 versions
respectively)
needs to be included in the
class path, either by putting it in the <TT
CLASS="ENVAR"
>CLASSPATH</TT
>
environment variable, or by using flags on the
<TT
CLASS="COMMAND"
>java</TT
> command line.
</P
><P
> For instance, I have an application that uses the
<SPAN
CLASS="ACRONYM"
>JDBC</SPAN
> driver to access a large database
containing astronomical objects. I have the application and the
<SPAN
CLASS="ACRONYM"
>JDBC</SPAN
> driver installed in the <TT
CLASS="FILENAME"
>/usr/local/lib</TT
> directory, and the
Java <SPAN
CLASS="ACRONYM"
>JDK</SPAN
> installed in
<TT
CLASS="FILENAME"
>/usr/local/jdk1.3.1</TT
>. To run the
application, I would use:
</P><PRE
CLASS="PROGRAMLISTING"
>export CLASSPATH=/usr/local/lib/finder.jar<A
NAME="CO.JDBC-FINDER"
><B
>(1)</B
></A
>:/usr/local/pgsql/share/java/postgresql.jar:.
java Finder</PRE
><P>
<DIV
CLASS="CALLOUTLIST"
><DL
COMPACT="COMPACT"
><DT
><A
HREF="jdbc.html#CO.JDBC-FINDER"
><B
>(1)</B
></A
></DT
><DD
> <TT
CLASS="FILENAME"
>finder.jar</TT
> contains the Finder application.
</DD
></DL
></DIV
>
</P
><P
> Loading the driver from within the application is covered in
<A
HREF="jdbc-use.html"
>Section 5.2</A
>.
</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="JDBC-PREPARE"
>5.1.3. Preparing the Database for <SPAN
CLASS="ACRONYM"
>JDBC</SPAN
></A
></H2
><P
> Because Java only uses TCP/IP connections, the
<SPAN
CLASS="APPLICATION"
>PostgreSQL</SPAN
> server must be configured to
accept TCP/IP connections. This can be done by setting
<TT
CLASS="LITERAL"
>tcpip_socket = true</TT
> in the
<TT
CLASS="FILENAME"
>postgresql.conf</TT
> file or by supplying the
<TT
CLASS="OPTION"
>-i</TT
> option flag when starting
<TT
CLASS="COMMAND"
>postmaster</TT
>.
</P
><P
> Also, the client authentication setup in the
<TT
CLASS="FILENAME"
>pg_hba.conf</TT
> file may need to be configured.
Refer to the <I
CLASS="CITETITLE"
>Administrator's Guide</I
> for
details. The <SPAN
CLASS="ACRONYM"
>JDBC</SPAN
> Driver supports the trust,
ident, password, md5, and crypt authentication methods.
</P
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