I want to get a parameter. The priority for getting that parameter is that I have to look for it in Table1, but if it doesn't exist there, I have to look for it in Table2. If not, so that parameter is null (this situation should not happen, but, well, there is always an edge case).

I wanted to try something like this:

```
SELECT NVL(
  SELECT paramValue from Table1
    where paramName = "paramName" and Id = "id", 
  SELECT paramValue from Table2
    where paramName = "paramName" and Id = "id")

```

But it gives me a syntax error.

Is there any way of doing something like this?