Using the JDBC Driver

This section provides quick start instructions for making a simple connection to a SQL Server database by using the Microsoft SQL Server JDBC Driver. Before you connect to a SQL Server database, SQL Server must first be installed on either your local computer or a server, and the JDBC driver must be installed on your local computer. 

Choosing the Right JAR file

The Microsoft SQL Server JDBC Driver provides sqljdbc.jar and sqljdbc4.jar class library files to be used depending on your preferred Java Runtime Environment (JRE) settings. For more information about which JAR file to choose, see System Requirements for the JDBC Driver.

Setting the Classpath

The JDBC driver is not part of the Java SDK. If you want to use it, you must set the classpath to include the sqljdbc.jar file or the sqljdbc4.jar file. If the classpath is missing an entry for sqljdbc.jar or sqljdbc4.jar, your application will throw the common "Class not found" exception.

The sqljdbc.jar file and sqljdbc4.jar file are installed in the following location:

<installation directory>\sqljdbc_<version>\<language>\sqljdbc.jar

<installation directory>\sqljdbc_<version>\<language>\sqljdbc4.jar

The following is an example of the CLASSPATH statement that is used for a Windows application:

CLASSPATH =.;C:\Program Files\Microsoft SQL Server JDBC Driver\sqljdbc_3.0\enu\sqljdbc.jar

The following is an example of the CLASSPATH statement that is used for a Unix/Linux application:

CLASSPATH =.:/home/usr1/mssqlserverjdbc/Driver/sqljdbc_3.0/enu/sqljdbc.jar

You must make sure that the CLASSPATH statement contains only one Microsoft SQL Server JDBC driver, such as either sqljdbc.jar or sqljdbc4.jar.

Applications that are run directly at the command prompt

The classpath is configured in the operating system. Append sqljdbc.jar or sqljdbc4.jar to the classpath of the system. Alternatively, you can specify the classpath on the Java command line that runs the application by using the java -classpath option.

Applications that run in an IDE

Each IDE vendor provides a different method for setting the classpath in its IDE. Just setting the classpath in the operating system will not work. You must add sqljdbc.jar or sqljdbc4.jar to the IDE classpath.

Servlets and JSPs

Servlets and JSPs are run in a servlet/JSP engine such as Tomcat. The classpath must be set according to the servlet/JSP engine documentation. Just setting the classpath in the operating system will not work. Some servlet/JSP engines provide setup screens that you can use to set the classpath of the engine. In that situation, you must append the correct JDBC Driver JAR file to the existing engine classpath and restart the engine. In other situations, you can deploy the driver by copying sqljdbc.jar or sqljdbc4.jar to a specific directory, such as lib, during engine installation. The engine driver classpath can also be specified in an engine specific configuration file.

Enterprise Java Beans

Enterprise Java Beans (EJB) are run in an EJB container. EJB containers are sourced from various vendors. Java applets run in a browser but are downloaded from a Web server. Copy sqljdbc.jar or sqljdbc4.jar to the Web server root and specify the name of the JAR file in the HTML archive tab of the applet, for example, <applet ... archive=sqljdbc.jar>.

Making a Simple Connection to a Database

Using the sqljdbc.jar class library, applications must first register the driver as follows:

Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

When the driver is loaded, you can establish a connection by using a connection URL and the getConnection method of the DriverManager class:

String connectionUrl = "jdbc:sqlserver://localhost:1433;" +
   "databaseName=AdventureWorks;user=MyUserName;password=*****;";
Connection con = DriverManager.getConnection(connectionUrl);

In the JDBC API 4.0, the DriverManager.getConnection method is enhanced to load JDBC drivers automatically. Therefore, applications do not need to call the Class.forName method to register or load the driver when using the sqljdbc4.jar class library.

When the getConnection method of the DriverManager class is called, an appropriate driver is located from the set of registered JDBC drivers. sqljdbc4.jar file includes "META-INF/services/java.sql.Driver" file, which contains the com.microsoft.sqlserver.jdbc.SQLServerDriver as a registered driver. The existing applications, which currently load the drivers by using the Class.forName method, will continue to work without modification.

For more information about how to connect with data sources and use a connection URL, see Building the Connection URL and Setting the Connection Properties.

See Also

Other Resources

Overview of the JDBC Driver