What is the primary benefit of using parameterized queries in ColdFusion when interacting with a database?

The primary benefit of using parameterized queries in ColdFusion when interacting with a database is to prevent SQL injection vulnerabilities. SQL injection is a security flaw that allows attackers to insert malicious SQL code into your database queries, potentially granting them unauthorized access to data, modifying data, or even taking control of the database server. Parameterized queries mitigate this risk by treating user-supplied input as data, rather than executable code.

Here's how it works: Instead of directly embedding user input into the SQL query string, you define placeholders (parameters) within the query. These placeholders are then populated with the user's input separately, at runtime, by the database driver. The database driver handles the proper escaping and quoting of the input, ensuring that it is treated as data and not as part of the SQL command itself.

For example, consider a query to retrieve a user's information based on their username:

Without Parameterization (Vulnerable):
```cfscript
query = "SELECT * FROM users WHERE username = '#username#';"
// username might come from a form input
```
If a user enters `' OR '1'='1` as the username, the resulting query becomes `SELECT * FROM users WHERE username = '' OR '1'='1';`. This malicious input bypasses the intended `WHERE` clause and could return all users in the table.

With Parameterization (Secure):
```cfscript
query = "SELECT * FROM users WHERE username = ?;";
query.execute(username)
// username might come from a form input
```
In this parameterized version, the `?` acts as a placeholder. The `query.execute(username)` method sends the query and the `username` value separately to the database. The database driver then handles the escaping and quoting of the `username` value, ensuring that it is treated as a literal string, even if it contains special characters. The database will interpret the `?` as a value to be substituted, not as SQL code to be executed.

ColdFusion's query objects (like `CFQUERY`, `CFSQL`, and the newer `query` object in CFScript) automatically support parameterized queries when you use placeholders like `?` or named parameters (e.g., `:username`). This separation of code and data is the core principle behind preventing SQL injection and maintaining database security. Parameterized queries also often improve performance because the database can cache the query plan and reuse it for multiple executions with different parameter values.