使用 JPA 和 Hibernate 时@Size、@Length 和 @Column(length=value) 的区别 [英] Difference between @Size, @Length and @Column(length=value) when using JPA and Hibernate

问题描述

下面三个字段的验证检查有什么区别?

What is the difference between the validation check of the following three fields?

@Entity
public class MyEntity {

    @Column(name = "MY_FIELD_1", length=13)
    private String myField1;
    @Column(name = "MY_FIELD_2")
    @Size(min = 13, max = 13)
    private String myField2;
    @Column(name = "MY_FIELD_3")
    @Length(min = 13, max = 13)
    private String myField3;

    // getter & setter

}

我读到第一个与 DDL 相关.第二个是用于 bean 验证.第三个是用于休眠验证.

I read that the first one has to do with DDL stuff. The second is for bean-validation. The third is for hibernate-validation.

这样对吗?我仍然不明白的是:我什么时候必须使用哪一个?这些注释之一何时触发?

Is that correct? What I still don't understand is: When do I have to use which one? When does one of these annotations trigger?

考虑以下情况:鉴于需要开发一个长度为 13 的字符串类型字段的实体.您会选择上述哪种方法?或者甚至更好:您必须问自己哪些问题才能找出哪个问题适合您的目的?

Think of the following situation: Given the requirement to develope an entity with a field of type string with length 13. Which of above mentioned methods would you choose? Or even better: Which questions do you have to ask yourself to find out which one suits your purposes?

推荐答案

1. @Column 是一个 JPA 注释，模式生成工具使用 length 属性来设置关联的 SQL 列长度.
2. @Size 是一个 Bean Validation 注释，用于验证关联的 String 是否具有长度受最小值和最大值限制的值.
3. @Length 是 Hibernate 特有的注解，与 @Size
含义相同

1. @Column is a JPA annotation and the length attribute is used by the schema generation tool to set the associated SQL column length.
2. @Size is a Bean Validation annotation that validates that the associated String has a value whose length is bounded by the minimum and maximum values.
3. @Length is a Hibernate-specific annotation and has the same meaning as @Size

所以 2. 和 3. 都应该使用 Bean Validation 来验证 String 的长度.我会选择 2. 因为它是通用的.

So both 2. and 3. should validate the String length using Bean Validation. I'd pick 2. because it's generic.

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