Talk:Jakarta Persistence Query Language: Difference between revisions

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{{WikiProject Javabanner shell|class=stubStub|importance=low}}

{{WikiProject Java|importance=low}}

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== Mistake in example? ==

This article currently has the following example:

<syntaxhighlight lang="java">

import javax.persistence.EntityManager;

import javax.persistence.Query;

import org.apache.commons.lang.StringUtils;

...

@SuppressWarnings("unchecked")

public List<Author> getAuthorsByLastName(String lastName) {

String queryString = "SELECT a FROM Author a " +

"WHERE :lastName IS NULL OR LOWER(a.lastName) = :lastName";

Query query = getEntityManager().createQuery(queryString);

query.setParameter("lastName", StringUtils.lowerCase(lastName));

return query.getResultList();

}

</syntaxhighlight>

(Keep in mind the Author class has a field <code>private String firstName</code>.)

The <code>WHERE :lastName IS NULL</code> part doesn't make sense to me. Shouldn't it be written <code>WHERE lastName IS NULL</code> (i.e., without the colon)? In case I'm wrong, can someone please explain the semantics of this query? --[[User:Abdull|Abdull]] ([[User talk:Abdull|talk]]) 15:20, 29 September 2012 (UTC)

== What is Author in the first query string? ==

Anyone just reading this page will be immediately close the page because it's not at all clear what is Author in the first query? I guess it's a class which has been shown before, so making a link to the source code makes reading this article much less annoying, maybe even pleasant...

[[Special:Contributions/92.195.55.224|92.195.55.224]] ([[User talk:92.195.55.224|talk]]) 18:47, 1 December 2012 (UTC)

Seems like it's because of a vandalism by the following entries:

(cur | prev) 09:39, 9 October 2012‎ 183.82.123.104 (talk)‎ . . (3,549 bytes) (-220)‎ . . (→‎Examples) (undo)

(cur | prev) 09:38, 9 October 2012‎ 183.82.123.104 (talk)‎ . . (3,769 bytes) (-300)‎ . . (→‎Examples) (undo)

Someone with more knowledge please fix it.

[[Special:Contributions/174.61.157.234|174.61.157.234]] ([[User talk:174.61.157.234|talk]]) 07:20, 12 December 2012 (UTC)