oracle merge insert if not exists
snippet in sql

oracle merge insert if not exists

user3387

merge into table1 t1
    using (select 'value1' as value1 ,value2 
           from table2 
           where table2.type = 'ok' ) t2
    on ( t1.value1 = t2.value1)
when not matched then
   insert values (t2.value1, t2.value2)
/