title: Android SQLite check if value exists
body: <p>I have a SQLite Database and insert some data like this, but now I would like to check first if this value is already in the database and only if its not insert it. How I can do this?</p>
  
  <pre><code>myDB = this.openOrCreateDatabase(MY_DB_NAME, MODE_PRIVATE, null);
  myDB.execSQL("INSERT INTO " + MY_DB_TABLE + "(db_datum)" 
   +"VALUES ('"+datum.getText().toString()+"');");
  </code></pre>