Comment by lores

> $req = "insert into people (name) ('$name')";

> $db.exec($req)

Now you have "null" as strings in the DB in any language that interpolates null as "null".

> select * from people where name is not null

"Why do we see nulls in testing? Damn, the DB has dirty data. Go through the trouble of fixing it, or...

> select * from people where name is not null and name != "null"

The end. Sorry Mr Null.