Defining the JDBC interface

Defining the profile

To define a connection through the JDBC interface, you must create a database profile by supplying values for at least the basic connection parameters in the Database Profile Setup - JDBC dialog box. You can then select this profile at any time to connect to your database in the development environment.

For information on how to define a database profile, see “Using database profiles”.

Specifying connection parameters

To provide maximum flexibility (as provided in the JDBC API), the JDBC interface supports database connections made with different combinations of connection parameters:

Driver name, URL, and Properties You should specify values for this combination of connection parameters if you need to define driver-specific properties. When properties are defined, you must also define the user ID and password in the properties field.

For example, when connecting to the jConnect driver, enter the following values in the Driver-Specific Properties field:
```
SQLINITSTRING=set TextSize 32000; user=system;password=manager;
```
Driver name, URL, User ID, and Password You should specify values for this combination of connection parameters if you do not need to define any driver-specific properties.
```
Driver Name: com.sybase.jdbc.SybDriver
```
```
URL:         jdbc:sybase:Tds:localhost:2638
```
```
Login ID:    dba
```
```
Password:    sql
```
Driver name and URL You should specify values for this combination of connection parameters when the user ID and password are included as part of the URL.

For example, when connecting to the Oracle JDBC driver, the URL can include the user ID and password:
```
jdbc:oracle:thin:userid/password@host:port:dbname
```

Specifying properties when connecting to jConnect If you plan to use the blob datatype in PowerBuilder, you should be aware that jConnect imposes a restriction on blob size. Consequently, before you make your database connection from PowerBuilder, you might want to reset the blob size to a value greater than the maximum size you plan to use.

To set blob size, define the jConnect property SQLINITSTRING in the Driver-Specific Properties box on the Connection page. The SQLINITSTRING property is used to define commands to be passed to the back-end database server:

SQLINITSTRING=set TextSize 32000;

Remember that if you define a property in the Driver-Specific Properties box, you must also define the user ID and password in this box.

Specifying the appropriate Java Virtual Machine (JVM)

Since the JDB interface supports several JVMs, you must specify which version of the JVM you want to use. For consistent behavior, the same version of the JVM used during development should be used at runtime.

Set the JavaVM DBParm on the Options tab page to select the appropriate JVM. The default value is JRE 1.4. Table 3-1 lists the supported JVMs and their corresponding JavaVM DBParm value.

**Table 3-1: Available Java VMs and JavaVM DBParm values**
JVM	DBParm Value
Sun JRE 1.2	Sun1.2
Sun JRE 1.3	Sun1.3
Sun JRE 1.4	Sun1.4

You do not need to set this DBParm for a PowerBuilder component running in EAServer.

Selecting the JVM for a component deployed to EAServer If a PowerBuilder component running in EAServer makes a database connection using JDBC, the JDB interface verifies that the JVM used by EAServer matches the JVM selected in the PowerBuilder database profile. If the versions do not match, the JDB interface overrides the profile setting and uses the EAServer JVM. It also enters a warning in the EAServer log file. (The EAServer log file records errors relating to component execution. You can view its contents using the Jaguar Manager File Viewer.)