我想在JPA中进行以下查询:
SELECT * FROM `happyDB`.`users` U WHERE U.party_as_user =1 AND U.party_party_id =2这很好,但是我的问题是我只将Party作为对象,而没有作为id,并且我无法使其工作.
在我要执行命名查询的Users实体中,我具有以下内容:
@JoinColumn(name = "pary_party_id", referencedColumnName = "party_id") @ManyToOne private Party partyId; @Column(name = "party_as_user") private Boolean partyAsUser;我试图像带点符号的对象一样实现它,但这不起作用:
@NamedQuery(name = "Users.findByPartyAsUser", query = "SELECT u FROM Users u WHERE u.partyAsUser = :partyAsUser AND u.partyId.partyId = :partyId")在Party对象中有一个名为partyId的属性,但是它不起作用.对此有什么解决方案吗?还是每次向Users中插入新的Party时,都必须向Users-bean添加一个属性,如private int partyID并填充它?
感谢您的帮助! 萨米·努尔米(Sami Nurmi)
解决方案通常,您可以在JPA中将对象用作参数,
SELECT u FROM Users u WHERE u.partyAsUser = :partyAsUser AND u.party = :party Party party = new Party(id); query.setParameter("party", party);但是,如果您使用正确的变量名,那么您应该可以使用
SELECT u FROM Users u WHERE u.partyAsUser = :partyAsUser AND u.party.id = :id如果您比对象更了解SQL,那么您始终可以使用本机SQL查询.
I would like to make this query in JPA:
SELECT * FROM `happyDB`.`users` U WHERE U.party_as_user =1 AND U.party_party_id =2This is working fine, but my problem is that I have Party only as an object, not as an id and I can't make it work.
In the Users-entity where I am trying to do the named query I have the following:
@JoinColumn(name = "pary_party_id", referencedColumnName = "party_id") @ManyToOne private Party partyId; @Column(name = "party_as_user") private Boolean partyAsUser;I tried to implement it like an object with dot notation, but that's not working:
@NamedQuery(name = "Users.findByPartyAsUser", query = "SELECT u FROM Users u WHERE u.partyAsUser = :partyAsUser AND u.partyId.partyId = :partyId")There is a property called partyId inside the Party-object, but it's not working. Is there any solution for that or do I have to add one property to the Users-bean like private int partyID and populate it every time when a new Party is inserted into Users?
Thanks for helping! Sami Nurmi
解决方案In general you can use an object as a parameter in JPA,
SELECT u FROM Users u WHERE u.partyAsUser = :partyAsUser AND u.party = :party Party party = new Party(id); query.setParameter("party", party);But what you have should work if you use the correct variable names, my guess is,
SELECT u FROM Users u WHERE u.partyAsUser = :partyAsUser AND u.party.id = :idAnd you can always use a native SQL query, if you understand SQL better than objects.
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