Possible Bug With JdbcTemplate getObject

[sethladd]

Hello,

The javadocs say that getObject(String, Object[], Class) will return NULL if the result of the query is NULL.

I am testing for a NULL in my unit tests, and instead of getting NULL from getObject, I get an exception:

org.springframework.dao.IncorrectResultSizeDataAccessException: Expected single row but found none
	at org.springframework.jdbc.core.JdbcTemplate$ObjectResultSetExtractor.extractData(JdbcTemplate.java:982)
	at org.springframework.jdbc.core.JdbcTemplate$1.doInPreparedStatement(JdbcTemplate.java:390)
	at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:334)
	at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:375)
	at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:411)
	at org.springframework.jdbc.core.JdbcTemplate.queryForObject(JdbcTemplate.java:470)
	at com.hic.eboss.dao.BrimsDAOJdbcImpl.getBusinessName(BrimsDAOJdbcImpl.java:99)
	at

I think this isn't correct, given the javadocs. I am using a CVS build right before 1.1 release (a few days before 1.1)

Am I misinterpreting the javadocs?

Thanks!
Seth

[Maarten]

The javadocs say that getObject(String, Object[], Class) will return NULL if the result of the query is NULL

You probably mean queryForObject ?

There is a difference between a query returning NULL and a query returning zero rows.

zero rows: select salary from emp where 1 = 2
null result: select max(salary) from emp where 1 = 2

I guess JdbcTemplate.queryForObject() will throw an exception for the first query and return null for the second query.

Maarten

[sethladd]

You probably mean queryForObject ?

Doh! You're right, I'm talking about queryForObject.

There is a difference between a query returning NULL and a query returning zero rows.

Ahh... I see. You're right. Thanks for clearing that up for me!

Seth

[acnesiac]

public UsuarioVO findUsuarioByLogin(String login) {
UsuarioVO usuarioVO = null;
try{
usuarioVO = (UsuarioVO)getJdbcTemplate().queryForObject("selec t * from where 1 = 2 ",new Object[] {login},new RowMapper());
}
catch (IncorrectResultSizeDataAccessException e) {
usuarioVO = null;
} return usuarioVO;
}


should i have to deal with the Exception like this or is there any other better and simple way to retrieve an object ?

thanks in advance !

[karldmoore]

There are a couple of options; you either find all results and manage the problems of what is returned yourself (e.g. no results, more that one, etc....) or you queryForObject() and manage the exceptions that are thrown. I'd prefer the latter as it handles most of the effort for you.