How to Find the Nearest Numerical Value in a Database Query?

Locating the Nearest Numerical Value in a Database

Envision a situation where you require a database query to retrieve a precise record matching your input or, in the absence of an exact match, the closest approximation. For instance, suppose you possess data with a 'Size' field corresponding to a specific value (e.g., 2) and an 'Area' field containing varied numerical values.

Consider the following query:

SELECT * FROM [myTable] 
WHERE Name = 'Test' AND Size = 2 AND PType = 'p' 
ORDER BY Area DESC

The intended outcome is for the query to identify a record that exactly matches your input ("Test" for the 'Name' field, 2 for the 'Size' field, and 'p' for the 'PType' field), prioritizing the 'Area' field in descending order. However, if no exact match exists, you seek to retrieve the record whose 'Area' value is closest to your input.

To accomplish this, utilize the following modified query:

SELECT TOP 1 * FROM [myTable] 
WHERE Name = 'Test' and Size = 2 and PType = 'p'
ORDER BY ABS( Area - @input ) 

This revised query incorporates the ABS() function, which computes the absolute value of the difference between the 'Area' field and your specified input. The ORDER BY clause arranges the results in ascending order based on the absolute value of the difference, ensuring that the record with the smallest difference (hence the closest numerical value to your input) is retrieved.

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