User Guide

Table Of Contents

Data type conversion 63

Date-time functions and queries when ODBC is not supported

Many CFML functions, including the Now, CreateDate, CreateTime, and CreateDateTime

functions, return date-time objects. ColdFusion creates Open Database Connectivity (ODBC)

timestamp values when it converts date-time objects to strings. As a result, you might get

unexpected results when using dates with a database driver that does not support ODBC escape

sequences, or when you use SQL in a query of queries.

If you use SQL to insert data into a database or in a WHERE clause to select data from a

database, and the database driver does not support ODBC-formatted dates, use the

DateFormat

function to convert the date-time value to a valid format for the driver. This rule also applies to

queries of queries.

For example, the following SQL statement uses the

DateFormat function in a query of queries to

select rows that have MyDate values in the future:

SELECT *

FROM DateQuery

WHERE MyDate >= '#DateFormat(Now())#'

</cfquery>

The following query of queries fails with the error message “Error: {ts is not a valid date,” because

the ColdFusion

Now function returns an ODBC timestamp:

SELECT *

FROM DateQuery

WHERE MyDate >= '#now()#'

</cfquery>

Using JavaCast with overloaded Java methods

You can overload Java methods so a class can have several identically named methods that differ

only in parameter data types. At runtime, the Java virtual machine attempts to resolve the specific

method to use, based on the types of the parameters passed in the call. Because ColdFusion does

not use explicit types, you cannot predict which version of the method the virtual machine will

use.

The ColdFusion

JavaCast function helps you ensure that the right method executes by

specifying the Java type of a variable, as in the following example:

The JavaCast function takes two parameters: a string representing the Java data type and the

variable whose type you are setting. You can specify the following Java data types: bool, int, long,

float, double, and String.

For more information on the

JavaCast function, see CFML Reference.