Why are my ColdFusion cfcharts blank when using parameterized queries with date values?

Troubleshooting Parametrized Queries in ColdFusion

ColdFusion's cfqueryparam tag provides a convenient mechanism to dynamically bind values to a SQL query. However, improper usage can lead to unexpected results, such as blank CFCharts.

Issue: Incorrect cfSQLType for Date Parameterization

When parameterizing a query with a date value, it is essential to specify the correct cfsqltype for the parameter. As demonstrated in this case, using an incorrect cfsqltype (e.g., CF_SQL_TIMESTAMP) for the YEAR() and MONTH() comparisons can disrupt the query's execution.

Incorrect Code:

<code class="coldfusion"><CFQUERYPARAM Value="#month#" cfsqltype="CF_SQL_TIMESTAMP">
<CFQUERYPARAM Value="#dateFormat(theMonth,"yyyy")#" cfsqltype="CF_SQL_TIMESTAMP"></code>

Causes: Type Mismatch and Database Conversion

Using the wrong cfsqltype introduces a type mismatch between the parameter value and the comparison column in the database. For example, YEAR() returns a four-digit integer, while CF_SQL_TIMESTAMP represents a full date/time object. This mismatch results in an incorrect comparison:

<code class="text">2014 = {ts '2009-02-13 23:31:30'}</code>

The underlying database automatically converts the parameter value to a number, leading to a false comparison and no matching records found for the query.

Resolution: Specify Correct cfsqltype

To resolve the issue, specify the appropriate cfsqltype for the parameters, ensuring that the data type matches the column type in the database:

<code class="coldfusion"><CFQUERYPARAM Value="#month#" cfsqltype="CF_SQL_INTEGER">
<CFQUERYPARAM Value="#dateFormat(theMonth,"yyyy")#" cfsqltype="CF_SQL_INTEGER"></code>

Alternative Approach:

As an alternative to parametrizing individual date components, the better approach is to use date comparisons with cf_sql_date as the cfsqltype:

<code class="coldfusion"><CFQUERYPARAM Value="#dateFormat(theMonth,"yyyy-mm-dd")#" cfsqltype="CF_SQL_DATE"></code>

This approach is more index-friendly and ensures accurate comparisons irrespective of whether the target column contains a date or a date/time value.

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