Count how many variables equal a target value

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The question:

Is there a smart way to count how many variables equal some target value (in SQL Server)?

For example, if I have:

declare @a int = 1;
declare @b int = 2;
declare @c int = 1;
declare @target int = 1;

Then I’d like to do how many of @a, @b, @c eqauls @target.

In imperative languages, it’s easy to make an inline array of the variables, and then count them – for example in JS:

var a = 1, b = 2, c = 2, target = 1;
if ([a, b, c].filter(item => item == target).length == 1)
   // do something

The equivalent in SQL of that “inline array” would be a single column table, but this would require using DECLARE TABLE, which I’d like to avoid.

Is there a similarly easy method for such counting in SQL?

Please note I’m less interested in “creating a table without declaring it” – what I really care about is the counting of variables against a target variable, so if it can be done without using tables at all, then it would be better.

The Solutions:

Below are the methods you can try. The first solution is probably the best. Try others if the first one doesn’t work. Senior developers aren’t just copying/pasting – they read the methods carefully & apply them wisely to each case.

Method 1

How about this solution?

declare @a int = 1;
declare @b int = 2;
declare @c int = 1;
declare @target int = 1;

SELECT COUNT(*)
FROM (VALUES (@a), (@b), (@c)) AS t(_value)
WHERE t._value = @target


All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0

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