How to update values using multiple primary keys [closed]

I have a table which contains multiple 3 primary keys and some other table contains 2 primary key using this primary keys I am going to update the values.

If it contains single primary key its getting updated but for 2-3 primary key its not getting matched and not updating. Can you please help me to get updated if it contains 2 or more primary keys.

Here is the code:

for i in range(len(col_INCR_list)):
            merge= "merge "+str(a)+" Target using "+str(a)+"_INCR Source on Source."+str(pk_INCR_list[0])+" = Target."+str(pk_list[0])+" when matched then update set Target."+str(col_list[i])+" =Source."+str(col_INCR_list[i])+" when not matched by target then insert ("+str(pk_list[0])+") values(Source."+str(pk_INCR_list[0])+");"
            print(merge)
            query=engine.execute(text(merge).execution_options(autocommit=True))
            print(query)