SQLite replacing data in existing column

Really new to SQLite and have a basic question that would help me a lot. If I have a table that looks like this:

_id   NAME
1     Mark
2     Bob

Let's say that I do an insert statement in to row 2 and put the name John. Will the table look like this:

_id   NAME
1     Mark
2     John

Or would I have to query the database, see if row 2 already contains a name, if it does, replace it with John? In other words, it doesn't automatically replace what's there?