Calculation Result Discrepancy, Col Mean, etc.

[#1]

Why do calculation results differ when using variables compared to using direct strings? I suspect that when variables are used, the grouping function for the variable part might not be working. How can this be resolved?

with the following formula

Col Mean(
	:data,
	:A,
	:B,
	:C_D == "ccccccc"
)

This is the formula.

Col Mean(
	:data,
	:A,
	:B,
	Column(Eval Insert("C_^get_input_1^" == get_input_2))
)

[#2]

Sorry, everyone. I forgot to mention that get_input_1 and get_input_2 can be assumed to be already obtained as strings, respectively.

[#3]

First one is comparing column vs string and second one we cannot be sure what is being compared (string to string which would always be 1 or 0?). At least it isn't evaluated and you will need to evaluate the values into the formula

Insert one expression into another using Eval Insert, Eval Expr, Parse, and Substitute 

[#4]

I want to achieve the same result as the expression in the first line. When the variables were given as get_input_1="D" and get_input_2="cccccc" respectively, I naturally expected the same result, but the reality was different...

[#5]

Eval(Substitute(
	Expr(Col Mean(
		:data,
		:A,
		:B,
		_input1_ == _input2_
	),
	Expr(_input1_) = NameExpr(AsColumn(dt, get_input_1)),
	Expr(_input2_) = get_input_2
	)
));

but you need to add new column and formula to that example

[#6]

Column(Eval Insert("C_^get_input_1^" == get_input_2)) evaluates to Column( "C_D" == "ccccccc" ), so your formula would be

edit

Including non-string inside Eval Insert() actually causes it to evaluate to the empty string.

Col Mean(
	:data,
	:A,
	:B,
	Column( "" )
);

That may be why it isn't working as expected.  Jarmo's solution should be what you want.