Handling variables in SQL Server - sql

Question

I have a procedure that needs to handle up to 60 different variables.
The variables have a standardized naming convention.
#TextParameter1 varchar(443) = NULL,
#TextParameter2 varchar(443) = NULL,
#TextParameter3 varchar(443) = NULL
I need to be able to check which variables are NULL and which aren't, and then handle the values of the non-null variables.
I tried using dynamic SQL to iterate over the variables by making the first portion of the variable name a string and iterating through the numbers on the end.
declare #rownum int = 1
while #rownum <= 60
declare #var_sql nvarchar(max) = 'INSERT INTO #slicer
SELECT IDENTITY(Int, 1, 1) AS rowkey, value
FROM STRING_SPLIT(CAST(#DetailQueryTextParameter' + CAST(#rownum AS nvarchar(3)) AS varchar(4000)), '^')'
execute #var_sql
Set #rownum = #rownum + 1
This will return an error claiming that #DetailQueryTextParameter needs to be declared first. What is the best way to handle all of these variables? I could do by writing a line of code for every single variable, but it seems like there is a better way. Can I insert the variable names into a table and iterate from there?

Answer 1

(The below was updated to include the SPLIT_STRING().)
You can use a VALUES subselect (not sure if that is the proper term) to combine all of your parameters into a single collection. You can then filter out the null values and pass the remaining values into STRING_SPLIT() using a CROSS APPLY.
DECLARE
#TextParameter1 varchar(443) = NULL,
#TextParameter2 varchar(443) = 'aaa^bbb',
#TextParameter3 varchar(443) = NULL,
#TextParameter4 varchar(443) = 'xxx^yyy^zzz',
#TextParameter5 varchar(443) = NULL
SELECT A.*, B.Value AS SplitValue
FROM (
VALUES
(1, #TextParameter1),
(2, #TextParameter2),
(3, #TextParameter3),
(4, #TextParameter4),
(5, #TextParameter5)
) A(Parameter, Value)
CROSS APPLY STRING_SPLIT(A.Value, '^') B
WHERE A.Value IS NOT NULL
Which would yield results like:
Parameter
Value
SplitValue
2
aaa^bbb
aaa
2
aaa^bbb
bbb
4
xxx^yyy^zzz
xxx
4
xxx^yyy^zzz
yyy
4
xxx^yyy^zzz
zzz
See this db<>fiddle.