Parameterize an SQL IN clause Examples

Let’s understand how to parameterize IN clause in SQL with some examples.

Example 1: Basic Parameterization

We will first set the variable and then select all by using the ‘*’ operator. And, to do that we’ll simply write the following query.

SET @ProductIDs = '1, 3, 5';

SELECT *
FROM Products
WHERE FIND_IN_SET(ProductID, @ProductIDs);

Output:

Explanation: In this example, I have used the ‘FIND_IN_SET‘ function to check whether the ‘ProductID‘ is present in the comma-separated list provided by ‘@ProductIDs‘.

Example 2: Using Parameters in Query

SET @ProductIDs = '1, 3, 5';

SELECT *
FROM Products
WHERE ProductID IN (
    SELECT CAST(value AS UNSIGNED)
    FROM (
        SELECT TRIM(SUBSTRING_INDEX(SUBSTRING_INDEX(@ProductIDs, ',', n.digit+1), ',', -1)) AS value
        FROM (
            SELECT 0 AS digit UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4
        ) n
        WHERE n.digit < LENGTH(@ProductIDs) - LENGTH(REPLACE(@ProductIDs, ',', '')) + 1
    ) AS split_values
);

Output:

Explanation: From this example, we can understand that it utilizes a strong split of the comma-separated values in ‘@ProductIDs‘ using nested ‘SELECT‘ statements.

Example 3: Parameterizing with Price Range

SET @PriceRange = '10.00, 15.00';

SELECT *
FROM Products
WHERE Price BETWEEN 
    (SELECT CAST(SUBSTRING_INDEX(@PriceRange, ',', 1) AS DECIMAL(10, 2))) 
    AND 
    (SELECT CAST(SUBSTRING_INDEX(@PriceRange, ',', -1) AS DECIMAL(10, 2)));

Output:

Explanation: In this example, I have set a parameter ‘@PriceRange‘ that represents a dynamic range of prices. Then the ‘BETWEEN‘ clause is used to filter the necessary rows where the product price falls within the specified range.

This shows how parameterizing the IN clause can extend to various scenarios. Also, it offers the adaptability to different filtering criteria.

The ‘IN‘ clause in SQL filters query results based on a specified list of values. It retrieves rows where a particular column matches any value within a provided list. Parameterizing the ‘IN’ clause adds flexibility to SQL queries, allowing for dynamic values, enhanced security, and efficient code reuse.

Before delving into the specifics of “Parameterizing an SQL IN clause,” it is essential to have a foundational understanding of SQL query syntax and the ‘IN’ clause itself. Familiarity with SQL queries and database structures is crucial for grasping parameterization concepts.