Update Updates a field condition of the current table with a field of another table is the field matching of the two tables

Update dt_roles t set t.pec_roles_key = (select n.int_code from bv_enum_values ​​n where t.role_name = n.value)

Update Table1 T1 set t1.column1 = (Select T2.Column2 from table2 t2 where)