Can I store a column name in an array? [duplicate] - sql

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I want to find the minimum value for a given row in a SQL table (where all values in the table other than the column names are integers), with only inputting the column names in one location.
In this example, Column_Names are = A, B, C, D, and E
Screenshot of Sample Table, where minimums are (7, 1, 11)
I got to a point where I can run this code and get the values for a given row. These values are stored in a temporary table, #Test, and the minimum value in #Test is stored in another temporary table, #Answers. I then use a While loop with a running counter to iterate through all the rows and find the minimum's of the rows. The list of minimums are in the temporary table, #Answers.
CREATE TABLE #Test (Calc INT);
CREATE TABLE #Answers (Minimum INT);
DECLARE #Counter INT
SET #Counter = 1
WHILE (#Counter <= (SELECT COUNT(Counter_Name) FROM #Data))
BEGIN
INSERT INTO #Test
SELECT A
FROM (SELECT ROW_NUMBER () OVER (ORDER BY (SELECT NULL)) AS RowNum, * FROM #Data) sub
WHERE
RowNum = #Counter
INSERT INTO #Test
SELECT B
FROM (SELECT ROW_NUMBER () OVER (ORDER BY (SELECT NULL)) AS RowNum, * FROM #Data) sub
WHERE
RowNum = #Counter
INSERT INTO #Test
SELECT C
FROM (SELECT ROW_NUMBER () OVER (ORDER BY (SELECT NULL)) AS RowNum, * FROM #Data) sub
WHERE
RowNum = #Counter
INSERT INTO #Test
SELECT D
FROM (SELECT ROW_NUMBER () OVER (ORDER BY (SELECT NULL)) AS RowNum, * FROM #Data) sub
WHERE
RowNum = #Counter
INSERT INTO #Test
SELECT E
FROM (SELECT ROW_NUMBER () OVER (ORDER BY (SELECT NULL)) AS RowNum, * FROM #Data) sub
WHERE
RowNum = #Counter
INSERT INTO #Answers
SELECT min(Calc) FROM #Test
DROP TABLE #Test
CREATE TABLE #Test (Calc INT);
SET #Counter = #Counter + 1
How can I run this code for a table with n number of columns? How do I generalize this code, or at the very least make it so that I don't have to copy & paste this whole piece of code for every column.:
INSERT INTO #Test
SELECT Counter_Name
FROM (SELECT ROW_NUMBER () OVER (ORDER BY (SELECT NULL)) AS RowNum, * FROM #Data) sub
WHERE
RowNum = #Counter
The ideal solution would be storing column names in an array and then iterate through that array using the above code. I have been unable to write up a working script for this step.

Answer 1

As alternative, you can use something like this:
create table #t (A INT, B INT, C INT, D INT, data varchar(30))
INSERT INTO #t
VALUES (1, 2, 3, 4,'test')
, (6, 5,7, 8,'test2')
, (9, 10, 11, 2,'test3')
SELECT *
FROM #t t
CROSS APPLY (
select ROW_NUMBER() over(order by v) as sort
, x.v
from (
VALUES
(A)
, (B)
, (C)
, (D)
) x (v)
) r
where sort = 1
You explode the A,B,C,D as values and then sort them by value and return the first one. If you need more columns, it's easy to add them to the VALUES(...) list.
You can also use GROUP BY if you have some good ID column in your #t table.