java - How can I use in clause with JPQL?

Question

I tried this code

   Query q = em.createQuery("SELECT c FROM Category c where c.id in 1" );

but I have this error

 An exception occurred while creating a query in EntityManager: 
    Exception Description: Syntax error parsing [SELECT c FROM Category c where c.id in 1]. 
    [31, 40] The expression is not a valid conditional expression.

what is the problem ?

Answer 1

请参阅JPQL 语言参考的第 10.2.5.8 段。它应该看起来像where c.id in (1)。

Answer 2

以下是文档中 IN 谓词的 JPQL 兼容示例。

1. select p from Payment p where type(p) in (CreditCardPayment, WireTransferPayment)

2. select c from Customer c where c.hqAddress.state in ('TX', 'OK', 'LA', 'NM')

3. select c from Customer c where c.hqAddress.state in ?

4. select c from Customer c where c.hqAddress.state in ( select dm.state from DeliveryMetadata dm where dm.salesTax is not null )

选项 2. 似乎您正在寻找什么，您可以尝试以下查询。

SELECT c FROM Category c where c.id in (1)

但是，如果您给出恒定的单个值，为什么您不使用它=。