Hi @Muavia_Shakeel ,
you can check How to setup a connection to Oracle Database with UiPath - #10 by urweeraratne
regards,
LNV
To add to the above link, I think the main issue is that you need to properly format your String input so that variables are recognized as variables and string as string.
Basic string:
"my Custom String"
Basic variable with a string:
"my Custom String"+variable1
Basic variable with a string that contains double quotes (you escape them with another double quote):
"my Custom String contains some escaped double quotes like so: "" "+variable1