Return number of rows affected by SQL UPDATE statement in Java

1. First of all, prepare the 'PreparedStatement' object using below constructor:

   PreparedStatement pStmt = con.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);
   //here variable 'sql' is your query ("UPDATE user_table SET Level = 'Super' WHERE Username = ?") 
   

2. Then, set your argument to 'pStmt'. In this case:

   prep1.setString(1, username);
   

3. Finally, executeUpdate and get affected rows as an integer

   int affectedRows = pStmt.executeUpdate();
   

Calling executeUpdate() on your PreparedStatement should return an int, the number of updated records.

Looking at this just now for another similar situation, where I only want to do additional work if something really changed, I think the most platform neutral way to do it would be to alter the query to exclude the case where the set fields match:

UPDATE user_table SET Level = 'Super' WHERE Username = ? AND Level <> 'Super'

Statement.executeUpdate() or execute() followed by getUpdateCount() will return the number of rows matched, not updated, according to the JDBC spec. If you want the updated count, you can specify useAffectedRows=true as a non-standard URL option. More information is available here.