轻松入门大数据第9章入门到进阶：如何快速掌握Hive DDL&DML 9.1 Hive DDL&DML 9.1.11 DDL之修改表实操

Bertha 。 2024-03-16 09:56 14阅读 0赞

### 轻松入门大数据 ###

#### 文章目录 ####

*   *  轻松入门大数据
     *   *  第9章 入门到进阶：如何快速掌握Hive DDL&DML
         *   *  9.1 Hive DDL&DML
             *   *  9.1.11 DDL之修改表实操

![在这里插入图片描述][bdb29ae697874ce8bb2e6f2d6c5fb0d1.png_pic_center]

#### 第9章 入门到进阶：如何快速掌握Hive DDL&DML ####

##### 9.1 Hive DDL&DML #####

> 1.  数据模型
> 2.  DDL之数据库
> 3.  DDL之表
> 4.  内部表vs外部表
> 5.  加载数据方式
> 6.  分区表
> 7.  Hive QL查询

###### 9.1.11 DDL之修改表实操 ######

官网文档：[https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DDL\#LanguageManualDDL-AlterTable/Partition/Column][https_cwiki.apache.org_confluence_display_Hive_LanguageManual_DDL_LanguageManualDDL-AlterTable_Partition_Column]

![在这里插入图片描述][9fc3d0aefeed4790a527755ce11a3980.png_pic_center]

【重命名表】

`alter table emp_managed rename to emp_managed_new;`

![在这里插入图片描述][4aa0ccad56db4b90b32e047176a889a8.png_pic_center]

看看HDFS

![在这里插入图片描述][3be5e67338cb4683bcb6aed7ff262869.png_pic_center]

也变了【老师的居然没变，离谱】

![在这里插入图片描述][8d8da07f0a214cbd90d0f0a50bafe4c8.png_pic_center]

![在这里插入图片描述][290b536ee6f54aac81bbff811f78e1a0.png_pic_center]

确实是变了，我再改回去看看

![在这里插入图片描述][5cbeb7d31d354216972034e97bcf81c4.png_pic_center]

![在这里插入图片描述][efab717d7ad44b3c99e93a57f6dfc471.png_pic_center]

确实变了【老师的离谱】

![在这里插入图片描述][fa1b56bf2e174738b6a2e097da1c505f.png_pic_center]

记住会变就行了。结果很明显。

【修改列】

创建一个新表进行测试：

create table dept(
    deptno int,
    dname string,
    loc string
    )ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t';

运行

![在这里插入图片描述][542aa8b2cb5f4aa8932c6b19b7cf5731.png_pic_center]

![在这里插入图片描述][3b7052a913474453a16f9af03bba7abc.png_pic_center]

直接加一个列

不指定位置：(会加在最后)

`alter table dept add columns(info string);`

![在这里插入图片描述][ece02f48f74e413aaacd89c70b51a668.png_pic_center]

修改列名：

`alter table dept change column info infos string;`

![在这里插入图片描述][e13be45ff7bc46798a2db088162d51b2.png_pic_center]

替换列：

`alter table dept replace columns(deptno string,dname string,loc string);`

![在这里插入图片描述][6aaa6aaafc76429a832321f2ef5472da.png_pic_center]

没问题。

[bdb29ae697874ce8bb2e6f2d6c5fb0d1.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/eb240d965257404db37ddcbc560f9353.png
[https_cwiki.apache.org_confluence_display_Hive_LanguageManual_DDL_LanguageManualDDL-AlterTable_Partition_Column]: https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DDL#LanguageManualDDL-AlterTable/Partition/Column
[9fc3d0aefeed4790a527755ce11a3980.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/1a6c47dd6494493fa3bc611dc523d6e7.png
[4aa0ccad56db4b90b32e047176a889a8.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/175582e0290a4cf9bbb0ec466d8236de.png
[3be5e67338cb4683bcb6aed7ff262869.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/b8cb579230464a66b0747df3fc01346a.png
[8d8da07f0a214cbd90d0f0a50bafe4c8.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/84769cf0bba44fb08849e26a8473d27e.png
[290b536ee6f54aac81bbff811f78e1a0.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/1acd90f35bbe46b184250691098e1196.png
[5cbeb7d31d354216972034e97bcf81c4.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/97f1afda755743159341217b41318de0.png
[efab717d7ad44b3c99e93a57f6dfc471.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/15b3d86788ab4251b451de9c125d3098.png
[fa1b56bf2e174738b6a2e097da1c505f.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/5dcbe7722aaa43b49cb05fa96f828c1a.png
[542aa8b2cb5f4aa8932c6b19b7cf5731.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/01b7affb30c8405cabda6319c18936b4.png
[3b7052a913474453a16f9af03bba7abc.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/b2309b982e7e486085f792eb423e8879.png
[ece02f48f74e413aaacd89c70b51a668.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/0feb105f36ae4035876b09507b0790da.png
[e13be45ff7bc46798a2db088162d51b2.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/81b10d47707446b68603875712323825.png
[6aaa6aaafc76429a832321f2ef5472da.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/45292a9ecdfc49e4b1157e8ec055f846.png