User Guide

Using Connection String Options 13
Limiting DSN definitions
Another use of the connect string feature is to limit data source name (DSN)
definitions. For example, if you are connecting to a server that has multiple
databases defined, you might not want to define a ColdFusion DSN for each
database. Instead, you can now use the connection string to supply the database
name for the single DSN that you defined for that server. The connection string
allows ColdFusion to support ODBC connections for databases that lack a data
source definition in the odbc.ini settings. All information required by the particular
ODBC driver to connect must be specified in the connection string.
Changes to the ColdFusion Administrator
The Settings page in the ColdFusion 5 Administrator includes a Connection String
option to support the connect string feature. You can specify a connect string in the
ColdFusion settings for an ODBC data source. If you specify a connectstring
attribute for a tag that supports the attribute, then it overrides the Administrator
setting.
Changes to CFML tags
A new connectstring attribute is now available in the following CFML tags:
•
cfquery
• cfinsert
• cfupdate
• cfstoredproc
• cfgridupdate
Using a connect string in a cached query
As with other query settings, when a query is cached, the connect string setting
becomes part of that cached query. The cache is purged only if the query is changed,
for example, if you change the data source name.
Use dynamic for dbtype attribute
When connecting to data sources dynamically with a connection string, the dbtype
attribute for tags making dynamic connections is set to
dbtype=dynamic. This
feature allows a ColdFusion application to run on multiple servers without requiring
odbc.ini Registry entries on each server. You must specify all information required by
the ODBC driver to connect in the
connectstring attribute. For ODBC connections
using the default dbtype (that is, dbtype=odbc), you can use the
connectstring
attribute to provide additional connection information or override connection
information that is specified in the DSN.