How do I write this JPA query that requires a JOIN? - spring

Question

I'm using JPA 2.0, Hibernate 4.1.0.Final, and Spring 3.1.1.RELEASE. I have two entities:
#Entity
#Table(name = "user",
uniqueConstraints = { #UniqueConstraint(columnNames = { "USER_NAME" }) }
)
public class User implements Comparable<User>, Serializable
{
...
#Column(name = "first_name")
#NotNull
/* the first name of the User */
private String firstName;
and
#Entity
#Table(name="code_user",
uniqueConstraints = {
#UniqueConstraint(columnNames = { "SAMPLE_WORD_ID", "USER_ID" }) }
)
public class CodeUser
{
#Id
#NotNull
#GeneratedValue(generator = "uuid-strategy")
#Column(name = "ID")
private String id;
#ManyToOne
#JoinColumn(name = "CODE_ID", nullable = false, updatable = true)
private Code code;
#ManyToOne
#JoinColumn(name = "USER_ID", nullable = false, updatable = true)
private User user;
How do I write a JPA/CriteriaBuilder query to find all User objects who's first name matches "Dave" and who are tied to a Code record in which the code is "abode"?

Answer 1

I might have missed an HQL syntax element
SELECT user FROM CodeUser codeUser
JOIN FETCH codeUser.user user
JOIN FETCH codeUser.code code
WHERE user.firstName = 'Dave' AND code.value = 'abode'
assuming Code has a field value holding the value "abode". You might not need the FETCH.
You can always replace the literal values with a placeholder like ? or a named placeholder like :name and set their values from the Query object.