Insert variables into database, if null, insert as is

Hi, using the database activity, I want to construct an SQL Insert statement with variables. How do I insert null(s) into the SQL table as-is and concatenate even if the variable values are null?

e.g. insert into table values( + var1 + , + var2, + var3 +) — this is a string!

if var1,var2,var3 are nulls in different combinations I don’t want to have to construct multiple if-else statements to handle each combination one by one

i.e. null object vs “null” string in insert statement

Usually to use variables in sql statement we need to put @ symbol with variable name
Like this
insert into yourtablename value (@strinput)

Where strinput is a string variable which concatenates those three variable values in a assign activity
Strinput = variable1 + variable2 + variable3


how does this concatenate/ does this work if the variable is null?

Yah it would like how usually a concatenation of string variable happens
It will take even null values