SQLJ connection technique 2: JDBC DriverManager interface

SQLJ connection technique 2 uses the JDBC DriverManager interface as the underlying means for creating the connection.

Procedure

To use SQLJ connection technique 2, follow these steps:

Execute an SQLJ connection declaration clause.
Doing this generates a connection context class. The simplest form of the connection declaration clause is:
```
#sql context context-class-name;
```
The name of the generated connection context class is context-class-name.
Load a JDBC driver by invoking the Class.forName method.
- Invoke Class.forName this way:
```
Class.forName("com.ibm.db2.jcc.DB2Driver");
```
  This step is unnecessary if you use the JDBC 4.0 driver or later.
Invoke the JDBC DriverManager.getConnection method.
Doing this creates a JDBC connection object for the connection to the data source. You can use any of the forms of getConnection that are specified in "Connect to a data source using the DriverManager interface with the IBM® Data Server Driver for JDBC and SQLJ".

The meanings of the url, user, and password parameters are:

url

A string that specifies the location name that is associated with the data source. That argument has one of the forms that are specified in "Connect to a data source using the DriverManager interface with the IBM Data Server Driver for JDBC and SQLJ". The form depends on which JDBC driver you are using.

user and password

Specify a user ID and password for connection to the data source, if the data source to which you are connecting requires them.
If the data source is a Db2 for z/OS® system, and you do not specify these parameters, Db2 uses the external security environment, such as the RACF® security environment, that was previously established for the user. For a CICS® connection, you cannot specify a user ID or password.
Invoke the constructor for the connection context class that you created in step 1
Doing this creates a connection context object that you specify in each SQL statement that you execute at the associated data source. The constructor invocation statement needs to be in the following form:
```
connection-context-class connection-context-object=
  new connection-context-class(Connection JDBC-connection-object);
```
The JDBC-connection-object parameter is the Connection object that you created in step 3.

Example

The following code uses connection technique 2 to create a connection to location NEWYORK. The connection requires a user ID and password, and does not require autocommit. The numbers to the right of selected statements correspond to the previously-described steps.

Figure 1. Using connection technique 2 to connect to a data source

#sql context Ctx;           // Create connection context class Ctx        1 
String userid="dbadm";      // Declare variables for user ID and password
String password="dbadm";
String empname;             // Declare a host variable
…
try {                       // Load the JDBC driver
  Class.forName("com.ibm.db2.jcc.DB2Driver");                             2 
}
catch (ClassNotFoundException e) {
   e.printStackTrace();
}
Connection jdbccon=                                                       3 
  DriverManager.getConnection("jdbc:db2://sysmvs1.stl.ibm.com:5021/NEWYORK",
    userid,password);
                              // Create JDBC connection object jdbccon
jdbccon.setAutoCommit(false); // Do not autocommit                       
Ctx myConnCtx=new Ctx(jdbccon);                                           4 
                              // Create connection context object myConnCtx
                              // for the connection to NEWYORK
#sql [myConnCtx] {SELECT LASTNAME INTO :empname FROM EMPLOYEE 
   WHERE EMPNO='000010'};  
                              // Use myConnCtx for executing an SQL statement