Lithicas Lithicas - 9 months ago 90
Java Question

Spring JDBC - .queryForObject() returns too many results?

I have this SQL statement:

return jdbcTemplate.queryForObject("SELECT * FROM materials WHERE title = ?", new MaterialMapper(), title);

And since I'm using .queryForObject I'm expecting to just get one or no results back. Instead I'm getting more than 1 result back which throws the IncorrectResultSizeDataAccessException exception. Any ideas?


The method queryForObject(sql, rowMapper, args) (and all the overload) declare explicitely to throw an IncorrectResultSizeDataAccessException if the query returns more than 1 row, or does not return anything:

Throws: IncorrectResultSizeDataAccessException - if the query does not return exactly one row

In your case, since the query SELECT * FROM materials WHERE title = ? can return more than 1 row, you have two choices:

  • Either use the query(sql, rowMapper, args) method instead, which returns a List of elements and not just a single row. You can then use it to retrieve only the first element (if the list isn't empty).
  • Adjust your query so that it returns a single row by limiting the result.