JDBC是否支持枚举？ [英] Are enums supported by JDBC?

问题描述

我真的找不到一个很好的枚举JDBC映射示例。
JDBC实际上支持枚举吗？

I really can't find a nice enum JDBC mapping example. Is enum actually supported by JDBC?

我正在使用MySQL。我有一个枚举列，并且想映射到一些Java枚举。

I am working with MySQL. I have an enum column, and would like to map to some Java enum.

推荐答案

JDBC不支持枚举。

JDBC does not support enums.

虽然您可以将字符串转换为枚举，所以如果您有Java枚举，则可以执行类似的操作

You can convert a string to an enum though, so if you have a Java enum you can do something like

 MyEnum enumVal =  MyEnum.valueOf(rs.getString("EnumColumn"));

尽管如此，您必须使Java枚举和mysql枚举保持同步。如果字符串中没有映射，则MyEnum.valueOf（）会引发IllegalArgumentException；如果从数据库中获得空值，则可能引发NullPointerException。

You'll have to keep your java enum and mysql enum in sync though. MyEnum.valueOf() can throw IllegalArgumentException if there's no mapping from the string, or NullPointerException if you get a null value from the db.

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