在Oracle中查找数字子类型(smallint，int等) [英] Find numeric subtype (smallint, int, etc) in oracle

问题描述

我在oracle中的oracle中添加了一个带有字段的表-

I added a table in oracle in oracle with fields -

• smallint
• int
• bigint

但是它在内部将它们存储为decimal(22,0)

But it internally store them as decimal(22,0)

有什么方法可以获取单个子类型(例如smallint )而不是十进制.

Is there any way to get individual subtype (e.g. smallint) instead of decimal.

我的用例:

我正在使用sqoop将数据从oracle复制到蜂巢.我需要检查oracle表的列的元数据，并将自己的oracle写为配置单元数据类型映射.

I am using sqoop to copy data from oracle to hive. I need to check metadata of columns of oracle table and wrote own oracle to hive data type mapping.

但是我总是得到decimal(22,0)，因此即使对于smallint，我也需要将所有这些列映射到hive表中的decimal(22,0).

But I am always getting decimal(22,0), so I need to map all these columns to decimal(22,0) in hive table even for smallint.

推荐答案

数据类型SMALLINT和INT只是ANSI/ISO标准类型，在Oracle中为

The data type SMALLINT and INT are just ANSI/ISO standard types which, in Oracle, are aliases for NUMBER(38) and the BIGINT datatype does not exist.

如果要存储2字节，4字节和8字节的值，则可以结合使用大小适当的NUMBER列和约束检查的组合，以确保数据在要求的范围内:

If you want to store 2-byte, 4-byte and 8-byte values then you can use a combination of appropriately sized NUMBER columns and constraint checking to ensure the data is within the required bounds:

CREATE TABLE table_name (
  small  NUMBER( 5,0) CHECK ( small  BETWEEN -POWER(2,15) AND +POWER(2,15)-1 ),
  medium NUMBER(10,0) CHECK ( medium BETWEEN -POWER(2,31) AND +POWER(2,31)-1 ),
  big    NUMBER(19,0) CHECK ( big    BETWEEN -POWER(2,63) AND +POWER(2,63)-1 )
);

INSERT INTO table_name VALUES ( -POWER(2,15), -POWER(2,31), -POWER(2,63) );
INSERT INTO table_name VALUES ( POWER(2,15)-1, POWER(2,31)-1, POWER(2,63)-1 );

然后:

SELECT * FROM table_name

输出:

SMALL  MEDIUM      BIG
------ ----------- --------------------
-32768 -2147483648 -9223372036854775808
 32767  2147483647  9223372036854775807

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