Java 我可以将 SQL 的 IN(...) 语句用于 namedQuery 吗？
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Can I use SQL's IN(...) statement for a namedQuery?
提问by kamaci
How can I use IN at my namedQuery?
如何在我的 namedQuery 中使用 IN？
@NamedQueries(
{
@NamedQuery(name = "GetAvailableProducts", query = new StringBuilder("").append("SELECT p FROM Product p WHERE p.type= :type AND (p.available IN ('I want to define changeable size of an array or sometinhg like that') OR p.available = :available)")),
}
I mean that I can set 'type' parameter (I defined it as a variable----> :type) and I want to define variables inside of IN statement to. However the number of parameters are not constant. I want to define an array or something like that :array[] and I want to set it when I call that namedQuery.
我的意思是我可以设置“type”参数（我将它定义为变量----> :type）并且我想在 IN 语句中定义变量。然而，参数的数量不是恒定的。我想定义一个数组或类似的东西 :array[] 并且我想在调用namedQuery时设置它。
采纳答案by Tadeusz Kopec
NamedQuery
命名查询
@NamedQueries(
{
@NamedQuery(name = "GetAvailableProducts", query = "FROM Product p WHERE p.type= :type AND (p.available IN (:availableCollection) OR p.available = :available)",
}
Set parameters
设置参数
Hibernate:
休眠：
query.setParameterList('availableCollection', yourCollection);
JPA:
JPA:
query.setParameter('availableCollection', yourCollection);
回答by AlexR
Did you try something like
你有没有尝试过类似的东西
SELECT p FROM Product p WHERE p.type= :type AND (p.available IN
('foo', 'bar') OR p.available = :available)
(if "available" is a string)
（如果“可用”是一个字符串）
or
或者
SELECT p FROM Product p WHERE p.type= :type AND (p.available IN
(1, 2, 3) OR p.available = :available)
(if available is a number)?
（如果可用是一个数字）？
回答by Art Licis
Expression 'IN' in JPQL is equal to writing multiple 'OR' statements, in your case an example of 'IN' would be:
JPQL 中的表达式“IN”等于编写多个“OR”语句，在您的情况下，“IN”的示例是：
... p.available IN ('US', 'GB') ...
Which I believe is equal to:
我认为这等于：
... p.available = 'US' OR p.available = 'GB' ...
Here's a link that explains it well: OpenJPA: IN Expression
这是一个解释得很好的链接：OpenJPA: IN Expression
EDITP.S. Assuming p.available is String (character type)
编辑PS 假设 p.available 是字符串（字符类型）
EDIT2The author has edited question so many times that I can't follow up him :) As for the actual question about passing array for IN-expression, here's a link of similar question on StackOverflow: JPQL IN clause - Arrays
EDIT2作者已经编辑了很多次问题，我无法跟进他:) 至于关于为 IN 表达式传递数组的实际问题，这里是 StackOverflow 上类似问题的链接：JPQL IN 子句 - 数组
