About JDBC
JDBC is a Java
Application Programming Interface (API) that you use to execute SQL
statements. JDBC enables an application, such as ColdFusion, to
interact with various database management systems (DBMSs), without
using interfaces that are database- and platform-specific.
The following
table describes the four types of JDBC drivers:
Type
|
Name
|
Description
|
|---|
1
|
JDBC-ODBC bridge
|
Translates JDBC calls to ODBC calls, and
sends them to the ODBC driver.
Advantages: Allows access
to many different databases.
Disadvantages: The ODBC driver,
and possibly the client database libraries, must reside on the ColdFusion
server computer. Performance is slower than other JDBC driver types.
Adobe
does not recommend this driver type unless your application requires
DBMS-specific features.
|
2
|
Native-API/partly Java driver
|
Converts JDBC calls to database-specific
calls.
Advantages: Better performance than Type 1 driver.
Disadvantages:
The client database libraries of the vendor must reside on the same
computer as ColdFusion.
ColdFusion includes a Type 2 driver
for use with Microsoft Access Unicode databases.
|
3
|
JDBC-Net pure Java driver
|
Translates JDBC calls to the middle-tier
server, which then translates the request to the database-specific
native-connectivity interface.
Advantages: The database libraries
of vendors are not required client computer. Can be tailored for small
size (faster loading).
Disadvantages: Database-specific code
must be executed in the middle tier.
ColdFusion includes an
ODBC socket Type 3 driver for use with Microsoft Access databases
and ODBC data sources.
|
4
|
Native-protocol/all-Java driver
|
Converts JDBC calls to the network protocol
used directly by the database.
Advantages: Fast performance.
No special software needed on the computer on which you run ColdFusion.
Disadvantages:
Many of these protocols are proprietary, requiring a different driver
for each database.
ColdFusion includes Type 4 drivers for
many DBMSs; however, not all DBMSs are supported in ColdFusion Standard
Edition.
|
JDBC drivers are stored in JAR files.
For example, the JDBC drivers that are supplied with ColdFusion
are in the _drivers.jar file. If you are using another JDBC driver,
you must store it in the ColdFusion classpath. For example, cf_root/cfusion/lib
(server configuration) or cf_webapp_root/WEB-INF/cfusion/lib
(multiserver or J2EE configuration).
Supplied drivers
The following table lists the database drivers supplied
with ColdFusion and where you can find more information about them:
To see a list of database versions that ColdFusion supports,
go to www.adobe.com/go/learn_cfu_cfsysreqs_en.
When running in the J2EE configuration, the ColdFusion Administrator
also lets you configure a data source that connects to a JNDI data
source. A Java Naming and Directory Interface (JNDI) data source
is equivalent to a ColdFusion data source, except you define it
by using your J2EE application server. After it’s defined, ColdFusion
applications use it as they would any data source. For information
on defining a JNDI data source, see Connecting to JNDI data sources.
