查询可能不存在的行的正确方法 - Java8

Question

I'm trying to write a method that will retrieve a row in a database. Around 50% of the time, this row will not exist. I tried using jdbcTemplate.queryForObject, but this resulted in exceptions being thrown if the row didn't exist in the DB. I don't think its good practice to try catch the method.

I read that if your data may be null, jdbcTemplate.query was a better choice. But I can only get it working if I return a list. Returning a list doesn't really make sense here, since I'm only selecting 1 row, that may or may not exist.

public List<LoanDetailsBean> getLoanDetailsByInsaddr(String insaddr) {
     String SQL_GET_LOAN_DETAILS_BY_INSADDR =
                "SELECT TOP 1 cip.tranchesize, " +
                        "             cip.maturitydate, " +
                        "             cip.moodysissuerrating, " +
                        "             cip.snpissuerrating, " +
                        "             cip.moodysassetrating, " +
                        "             cip.snpassetrating " +
                        "FROM   cloinstrumentproperty cip " +
                        "WHERE  insaddr = ? " +
                        "ORDER  BY updatedtime DESC ";

     return isdbJdbcTemplate.query(SQL_GET_LOAN_DETAILS_BY_INSADDR, new Object[] { insaddr }, (rs, rowNum) ->
             new LoanDetailsBean(
                  rs.getDouble("tranchesize"),
                  rs.getString("maturitydate"),
                  rs.getString("moodysissuerrating"),
                  rs.getString("snpissuerrating"),
                  rs.getString("moodysassetrating"),
                  rs.getString("snpassetrating")
             )
     );
}

How can I re-write this to make a little more sense?

Answer 1

Is there an option to use 3rd-party libraries in your project?

this could be done musch simpler with my own:

<dependency>
   <groupId>com.github.buckelieg</groupId>
   <artifactId>db-fn</artifactId>
   <version>0.3.4</version>
</dependency>

and then:

public List<LoanDetailsBean> getLoanDetailsByInsaddr(String insaddr) {
    try (DB db = new DB("jdbc:postgresql://host:port/database?user=user&password=pass")) {
         return db.select("SELECT TOP 1 cip.tranchesize, cip.maturitydate, cip.moodysissuerrating, cip.snpissuerrating, cip.moodysassetrating, cip.snpassetrating FROM cloinstrumentproperty cip WHERE insaddr=? ORDER BY updatedtime DESC", insaddr)
             .list(rs -> new LoanDetailsBean(rs.getDouble("tranchesize"), rs.getString("maturitydate"), rs.getString("moodysissuerrating"), rs.getString("snpissuerrating"), rs.getString("moodysassetrating"), rs.getString("snpassetrating"))));
    }
}