Create a Data Access Object for SQL Server Data using JDBI

JDBI is a SQL convenience library for Java that exposes two different style APIs, a fluent style and a SQL object style. The CData JDBC Driver for SQL Server integrates connectivity to live SQL Server data in Java applications. By pairing these technologies, you gain simple, programmatic access to SQL Server data. This article explains how to build a basic Data Access Object (DAO) and the accompanying code to read and write SQL Server data.

Create a DAO for the SQL Server Orders Entity

The interface below declares the desired behavior for the SQL object to create a single method for each SQL statement to be implemented.

public interface MyOrdersDAO {
 //insert new data into SQL Server
 @SqlUpdate("INSERT INTO Orders (ShipCountry, Freight) values (:shipCountry, :freight)")
 void insert(@Bind("shipCountry") String shipCountry, @Bind("freight") String freight);

 //request specific data from SQL Server (String type is used for simplicity)
 @SqlQuery("SELECT Freight FROM Orders WHERE ShipCountry = :shipCountry")
 String findFreightByShipCountry(@Bind("shipCountry") String shipCountry);

 /*
 * close with no args is used to close the connection
 */
 void close();
}

Open a Connection to SQL Server

Collect the necessary connection properties and construct the appropriate JDBC URL for connecting to SQL Server.

Connecting to Microsoft SQL Server

Connect to Microsoft SQL Server using the following properties:

• Server: The name of the server running SQL Server.
• User: The username provided for authentication with SQL Server.
• Password: The password associated with the authenticating user.
• Database: The name of the SQL Server database.

Connecting to Azure SQL Server and Azure Data Warehouse

You can authenticate to Azure SQL Server or Azure Data Warehouse by setting the following connection properties:

• Server: The server running Azure. You can find this by logging into the Azure portal and navigating to "SQL databases" (or "SQL data warehouses") -> "Select your database" -> "Overview" -> "Server name."
• User: The name of the user authenticating to Azure.
• Password: The password associated with the authenticating user.
• Database: The name of the database, as seen in the Azure portal on the SQL databases (or SQL warehouses) page.

SSH Connectivity for SQL Server

You can use SSH (Secure Shell) to authenticate with SQL Server, whether the instance is hosted on-premises or in supported cloud environments. SSH authentication ensures that access is encrypted (as compared to direct network connections).

SSH Connections to SQL Server in Password Auth Mode

To connect to SQL Server via SSH in Password Auth mode, set the following connection properties:

• User: SQL Server User name
• Password: SQL Server Password
• Database: SQL Server database name
• Server: SQL Server Server name
• Port: SQL Server port number like 3306
• UserSSH: "true"
• SSHAuthMode: "Password"
• SSHPort: SSH Port number
• SSHServer: SSH Server name
• SSHUser: SSH User name
• SSHPassword: SSH Password

SSH Connections to SQL Server in Public Key Auth Mode

To connect to SQL Server via SSH in Password Auth mode, set the following connection properties:

• User: SQL Server User name
• Password: SQL Server Password
• Database: SQL Server database name
• Server: SQL Server Server name
• Port: SQL Server port number like 3306
• UserSSH: "true"
• SSHAuthMode: "Public_Key"
• SSHPort: SSH Port number
• SSHServer: SSH Server name
• SSHUser: SSH User name
• SSHClientCret: the path for the public key certificate file

Built-in Connection String Designer

For assistance in constructing the JDBC URL, use the connection string designer built into the SQL Server JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.

java -jar cdata.jdbc.sql.jar

Fill in the connection properties and copy the connection string to the clipboard.

👁 Using the built-in connection string designer to generate a JDBC URL (Salesforce is shown.)

A connection string for SQL Server will typically look like the following:

jdbc:sql:User=myUser;Password=myPassword;Database=NorthWind;Server=myServer;Port=1433;

Use the configured JDBC URL to obtain an instance of the DAO interface. The particular method shown below will open a handle bound to the instance, so the instance needs to be closed explicitly to release the handle and the bound JDBC connection.

DBI dbi = new DBI("jdbc:sql:User=myUser;Password=myPassword;Database=NorthWind;Server=myServer;Port=1433;");
MyOrdersDAO dao = dbi.open(MyOrdersDAO.class);

//do stuff with the DAO

dao.close();

Read SQL Server Data

With the connection open to SQL Server, simply call the previously defined method to retrieve data from the Orders entity in SQL Server.

//disply the result of our 'find' method
String freight = dao.findFreightByShipCountry("USA");
System.out.println(freight);

Write SQL Server Data

It is also simple to write data to SQL Server, using the previously defined method.

//add a new entry to the Orders entity
dao.insert(newShipCountry, newFreight);

Since the JDBI library is able to work with JDBC connections, you can easily produce a SQL Object API for SQL Server by integrating with the CData JDBC Driver for SQL Server. Download a free trial and work with live SQL Server data in custom Java applications today.