Problem
The application wants to set a default datasource for all queries instead of specifying the datasource attribute of the <cfquery> tag with every call.
Solution
ColdFusion 9 introduced the ability to set a default datasource for an application.
Detailed explanation
Before ColdFusion 9 every <cfquery> tag had to have a datasource attribute that specified the datasource for ColdFusion to execut the particular query on.
For example:
<cfquery datasource="wine" name="qGetWine"> SELECT * FROM tbl_wine </cfquery>
The above <cfquery> would select all records from the table tbl_wine in the database that was specified in the datasource. One way around having to specify the datasource was to set an application variable to hold that value and then use that variable in place of the hardcoded value.
The same query from above using this method would look like this:
<cfquery datasource="#application.dsn#" name="qGetWine"> SELECT * FROM tbl_wine </cfquery>
With ColdFusion 9 all that has to happen is setting datasource variables in the Application.cfc
<cfcomponent> <cfset this.name = "wineDB" /> <cfset this.datasource = "wine"> </cfcomponent>
Now, by having set this variable the application does not have to reference the datasource attribute when using <cfquery>. The wine datsource will now be used by default if no datasource is specified. This datasource will also be used with <cfstoredproc> as well.
So the example from above becomes:
<cfquery name="qGetWine"> SELECT * FROM tbl_wine </cfquery>
This new feature will save lots of time!
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