将 java.long 映射到 oracle.Number(14)
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Mapping java.long to oracle.Number(14)
提问by x.509
I have db column whose datatype is Number (15) and i have the corresponding field in java classes as long. The question is how would i map it using java.sql.Types.
我有数据类型为 Number (15) 的 db 列，并且我在 java 类中有相应的字段long。问题是我将如何使用java.sql.Types映射它。
- would Types.BIGINT work?
- Or shall i use something else?
- Types.BIGINT 会起作用吗？
- 还是我应该用别的东西？
P.S: I can't afford to change the datatype within java class and within DB.
PS：我负担不起在 java 类和 DB 中更改数据类型。
回答by Mike
回答by robododge
A good place to find reliable size mappings between Java and Oracle Types is in the Hibernate ORM tool. Documented in the code here, Hibernate uses an Oracle NUMBER(19,0) to represent a java.sql.Types.BIGINT which should map to a long primitave
在 Hibernate ORM 工具中找到 Java 和 Oracle 类型之间可靠的大小映射的好地方。记载在这里的代码，休眠使用Oracle NUMBER（19,0）来表示java.sql.Types.BIGINT应映射到一个长primitave
回答by FGreg
I had a similar problem where I couldn't modify the Java Type or the Database Type. In my situation I needed to execute a native SQL query (to be able to utilize Oracle's Recursive query abilities) and map the result set to a non-managed entity (essentially a simple pojo class).
我有一个类似的问题，我无法修改 Java 类型或数据库类型。在我的情况下，我需要执行本机 SQL 查询（以便能够利用 Oracle 的递归查询功能）并将结果集映射到非托管实体（本质上是一个简单的 pojo 类）。
I found a combination of addScalarand setResultTransformerworked wonders.
我发现addScalar和setResultTransformer的组合创造了奇迹。
hibernateSes.createSQLQuery("SELECT \n"
+ " c.notify_state_id as \"notifyStateId\", \n"
+ " c.parent_id as \"parentId\",\n"
+ " c.source_table as \"sourceTbl\", \n"
+ " c.source_id as \"sourceId\", \n"
+ " c.msg_type as \"msgType\", \n"
+ " c.last_updt_dtm as \"lastUpdatedDateAndTime\"\n"
+ " FROM my_state c\n"
+ "LEFT JOIN my_state p ON p.notify_state_id = c.parent_id\n"
+ "START WITH c.notify_state_id = :stateId\n"
+ "CONNECT BY PRIOR c.notify_state_id = c.parent_id")
.addScalar("notifyStateId", Hibernate.LONG)
.addScalar("parentId", Hibernate.LONG)
.addScalar("sourceTbl",Hibernate.STRING)
.addScalar("sourceId",Hibernate.STRING)
.addScalar("msgType",Hibernate.STRING)
.addScalar("lastUpdatedDateAndTime", Hibernate.DATE)
.setParameter("stateId", notifyStateId)
.setResultTransformer(Transformers.aliasToBean(MyState.class))
.list();
Where notifyStateId, parentId, sourceTbl, sourceId, msgType, and lastUpdatedDateAndTimeare all properties of MyState.
其中notifyStateId、parentId、sourceTbl、sourceId、msgType和lastUpdatedDateAndTime都是 的属性MyState。
Without the addScalar's, I would get a java.lang.IllegalArgumentException: argument type mismatchbecause Hibernate was turning Oracle's Numbertype into a BigDecimalbut notifyStateIdand parentIdare Longtypes on MyState.
如果没有addScalar's，我会得到 a，java.lang.IllegalArgumentException: argument type mismatch因为 Hibernate 正在将 Oracle 的Number类型转换为 a BigDecimalbutnotifyStateId并且parentId是Long类型 on MyState。
回答by Tarcísio Júnior
I always use wrapper type, because wrapper types can be express null values.
我总是使用包装器类型，因为包装器类型可以表示空值。
In this case I will use Long wrapper type.
在这种情况下，我将使用 Long 包装器类型。
