Mapping DF > Expression-based SQL Query

[Deleted]

Hello community,
I'm trying to write an expression-based SQL Query in source definition,
that query contains quotes that cannot be parsed by expression language
I cannot find a way to identify those quotes as quotes inside a SQL query

Original SQL Query :
SELECT distinct col1,col2, HASHBYTES( 'MD5', CONCAT(col1,col2)) as HASH FROM table_name

Expression = 

'SELECT distinct '
+ $param_1
+ ' ,HASHBYTES( 'MD5' ,CONCAT(' + $param_1 + ')) as HASH FROM table_name'

PS = double quotes '' does not work

any help ?

Regards