title: H2 insert row only if doesn't exist
body: <p>I am using the H2 file database and I am running into the following problem.  Suppose I have a table called PROPERTIES with two VARCHAR(255) columns: NAME and VALUE, with NAME being the primary key.  Now, I would like to update the table with a new row only if it doesn't exist.  If it exists, I don't want to change the VALUE for that NAME.  This would be easy on say MS SQL Server, but the H2 SQL does not have IF, WHERE NOT EXISTS.  It does have a command called MERGE but that updates if exists.  Is there a way to do this with H2 SQL?<br>
  I don't believe this question is a duplicate because I haven't seen it asked for H2 specifically.</p>