hive常见操作

配置元数据存储到mysql数据库

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<?xml version="1.0"?> <?xml-stylesheet type="text/xsl" href="configuration.xsl"?> <configuration>     <property>       <name>javax.jdo.option.ConnectionURL</name>       <value>jdbc:mysql://hadoop102:3306/metastore?createDatabaseIfNotExist=true</value>       <description>JDBC connect string for a JDBC metastore</description>     </property>       <property>       <name>javax.jdo.option.ConnectionDriverName</name>       <value>com.mysql.jdbc.Driver</value>       <description>Driver class name for a JDBC metastore</description>     </property>       <property>       <name>javax.jdo.option.ConnectionUserName</name>       <value>root</value>       <description>username to use against metastore database</description>     </property>       <property>       <name>javax.jdo.option.ConnectionPassword</name>       <value>000000</value>       <description>password to use against metastore database</description>     </property> </configuration>

　基本数据类型

Hive数据类型	Java数据类型	长度	例子
TINYINT	byte	1byte有符号整数	20
SMALINT	short	2byte有符号整数	20
INT	int	4byte有符号整数	20
BIGINT	long	8byte有符号整数	20
BOOLEAN	boolean	布尔类型，true或者false	TRUE  FALSE
FLOAT	float	单精度浮点数	3.14159
DOUBLE	double	双精度浮点数	3.14159
STRING	string	字符系列。可以指定字符集。可以使用单引号或者双引号。	‘now is the time’ “for all good men”
TIMESTAMP		时间类型
BINARY		字节数组

 

集合数据类型

数据类型	描述	语法示例
STRUCT	和c语言中的struct类似，都可以通过“点”符号访问元素内容。例如，如果某个列的数据类型是STRUCT{first STRING, last STRING},那么第1个元素可以通过字段.first来引用。	struct()
MAP	MAP是一组键-值对元组集合，使用数组表示法可以访问数据。例如，如果某个列的数据类型是MAP，其中键->值对是’first’->’John’和’last’->’Doe’，那么可以通过字段名[‘last’]获取最后一个元素	map()
ARRAY	数组是一组具有相同类型和名称的变量的集合。这些变量称为数组的元素，每个数组元素都有一个编号，编号从零开始。例如，数组值为[‘John’, ‘Doe’]，那么第2个元素可以通过数组名[1]进行引用。	Array()

建表语句实例

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create table test( name string, friends array<string>, children map<string, int>, address struct<street:string, city:string> ) row format delimited fields terminated by ',' collection items terminated by '_' map keys terminated by ':' lines terminated by '\n';

DDL语句

建表语法

CREATE [EXTERNAL] TABLE [IF NOT EXISTS] table_name 
[(col_name data_type [COMMENT col_comment], ...)] 
[COMMENT table_comment] 
[PARTITIONED BY (col_name data_type [COMMENT col_comment], ...)] 
[CLUSTERED BY (col_name, col_name, ...) 
[SORTED BY (col_name [ASC|DESC], ...)] INTO num_buckets BUCKETS] 
[ROW FORMAT row_format] 
[STORED AS file_format] 
[LOCATION hdfs_path]

 管理表

更新列

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1	ALTER TABLE table_name CHANGE [COLUMN] col_old_name col_new_name column_type [COMMENT col_comment] [FIRST|AFTER column_name]

　　

增加和替换列

ALTER TABLE table_name ADD|REPLACE COLUMNS (col_name data_type [COMMENT col_comment], ...)

 

 DML语句

数据导入

load导入数据

load data [local] inpath '/opt/module/datas/student.txt' overwrite | into table student [partition (partcol1=val1,…)];

insert导入数据

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insert into table  student partition(month='201709') values(1,'wangwu'); insert overwrite table student partition(month='201708')              select id, name from student where month='201709'; from student               insert overwrite table student partition(month='201707')               select id, name where month='201709'               insert overwrite table student partition(month='201706')               select id, name where month='201709';<br><br>

 创建表导入数据

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create table if not exists student5(               id int, name string               )               row format delimited fields terminated by '\t'               location '/user/hive/warehouse/student5'; dfs -put /opt/module/datas/student.txt /user/hive/warehouse/student5;

import导入数据

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1 2	import table student2 partition(month='201709') from  '/user/hive/warehouse/export/student';