2.1-2.2 Hive 中数据库(Table、Database)基本操作

官网文档：https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DDL

一、create table

1、官方字段

#
#
CREATE [TEMPORARY] [EXTERNAL] TABLE [IF NOT EXISTS] [db_name.]table_name
-- (Note: TEMPORARY available in Hive 0.14.0 and later)
[(col_name data_type [COMMENT col_comment], ... [constraint_specification])]
[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]
[SKEWED BY (col_name, col_name, ...)
-- (Note: Available in Hive 0.10.0 and later)]
ON ((col_value, col_value, ...), (col_value, col_value, ...), ...)
[STORED AS DIRECTORIES]
[
[ROW FORMAT row_format]
[STORED AS file_format]
| STORED BY 'storage.handler.class.name' [WITH SERDEPROPERTIES (...)]
-- (Note: Available in Hive 0.6.0 and later)
]
[LOCATION hdfs_path]
[TBLPROPERTIES (property_name=property_value, ...)]
-- (Note: Available in Hive 0.6.0 and later)
[AS select_statement];
-- (Note: Available in Hive 0.5.0 and later; not supported for external tables)
CREATE [TEMPORARY] [EXTERNAL] TABLE [IF NOT EXISTS] [db_name.]table_name
LIKE existing_table_or_view_name
[LOCATION hdfs_path];
data_type
: primitive_type
| array_type
| map_type
| struct_type
| union_type
-- (Note: Available in Hive 0.7.0 and later)
primitive_type
: TINYINT
| SMALLINT
| INT
| BIGINT
| BOOLEAN
| FLOAT
| DOUBLE
| DOUBLE PRECISION -- (Note: Available in Hive 2.2.0 and later)
| STRING
| BINARY
-- (Note: Available in Hive 0.8.0 and later)
| TIMESTAMP
-- (Note: Available in Hive 0.8.0 and later)
| DECIMAL
-- (Note: Available in Hive 0.11.0 and later)
| DECIMAL(precision, scale)
-- (Note: Available in Hive 0.13.0 and later)
| DATE
-- (Note: Available in Hive 0.12.0 and later)
| VARCHAR
-- (Note: Available in Hive 0.12.0 and later)
| CHAR
-- (Note: Available in Hive 0.13.0 and later)
array_type
: ARRAY < data_type >
map_type
: MAP < primitive_type, data_type >
struct_type
: STRUCT < col_name : data_type [COMMENT col_comment], ...>
union_type
: UNIONTYPE < data_type, data_type, ... >
-- (Note: Available in Hive 0.7.0 and later)
row_format
: DELIMITED [FIELDS TERMINATED BY char [ESCAPED BY char]] [COLLECTION ITEMS TERMINATED BY char]
[MAP KEYS TERMINATED BY char] [LINES TERMINATED BY char]
[NULL DEFINED AS char]
-- (Note: Available in Hive 0.13 and later)
| SERDE serde_name [WITH SERDEPROPERTIES (property_name=property_value, property_name=property_value, ...)]
file_format:
: SEQUENCEFILE
| TEXTFILE
-- (Default, depending on hive.default.fileformat configuration)
| RCFILE
-- (Note: Available in Hive 0.6.0 and later)
| ORC
-- (Note: Available in Hive 0.11.0 and later)
| PARQUET
-- (Note: Available in Hive 0.13.0 and later)
| AVRO
-- (Note: Available in Hive 0.14.0 and later)
| JSONFILE
-- (Note: Available in Hive 4.0.0 and later)
| INPUTFORMAT input_format_classname OUTPUTFORMAT output_format_classname
constraint_specification:
: [, PRIMARY KEY (col_name, ...) DISABLE NOVALIDATE ]
[, CONSTRAINT constraint_name FOREIGN KEY (col_name, ...) REFERENCES table_name(col_name, ...) DISABLE NOVALIDATE

2、建表例子

例子1、2

##################栗子#####################
--------------------------------------------------------------------------------------------
create table IF NOT EXISTS default.bf_1og_20150913
#在default库下创建一个表，不存在则创建；
(
ip string COMMENT 'remote ip address',
#COMMENT：字段注释
user string,
req_url string COMMENT 'user request url'
)
COMMENT ' BeiFeng Web Access Logs'
#表注释
ROW FORMAT DELIMITED FIELDS TERMINATED BY‘ ’
#hive的数据存在hdfs上，此项指定数据文件中列之间的间隔符
STORED AS TEXTFILE
#数据格式
LOCATION '/user/bf/hive/warehouse/bf_log_201501913'
#表的存储路径，可以自己指定
--------------------------------------------------------------------------------------------
create table IF NOT EXISTS default.bf_1og_20150913_sa
AS select ip, req_url from default.bf_log_20150913;
#创建一个表，此表的字段来源于查询另外一个表

例子3

################################
create table IF NOT EXISTS default.bf_log_20150914
like default.bf_log_20150913
#根据另外一张表来创建表

二、演示

1、建表

#创建表
hive (default)> create table IF NOT EXISTS default.bf_1og_20150913(
> ip string COMMENT 'remote ip address',
> user string,
> req_url string COMMENT 'user request url')
> COMMENT 'BeiFeng Web Access Logs'
> ROW FORMAT DELIMITED FIELDS TERMINATED BY' '
> STORED AS TEXTFILE;
OK
Time taken: 0.361 seconds
hive (default)> show tables;
OK
tab_name
bf_1og_20150913
bf_log
Time taken: 0.052 seconds, Fetched: 2 row(s)

2、导入数据

#########
hive (default)> load data local inpath '/opt/datas/bf-log.txt' into table default.bf_1og_20150913;
Copying data from file:/opt/datas/bf-log.txt
Copying file: file:/opt/datas/bf-log.txt
Loading data to table default.bf_1og_20150913
Table default.bf_1og_20150913 stats: [numFiles=1, numRows=0, totalSize=141, rawDataSize=0]
OK
Time taken: 0.36 seconds
#########
hive (default)> select * from default.bf_1og_20150913;
OK
bf_1og_20150913.ip
bf_1og_20150913.user
bf_1og_20150913.req_url
"27.38.5.159"
"-"
"31/Aug/2015:00:04:53
"27.38.5.159"
"-"
"31/Aug/2015:00:04:37
"27.38.5.159"
"-"
"31/Aug/2015:00:04:53
Time taken: 0.156 seconds, Fetched: 3 row(s)

3、第二种建表例子

#建表
hive (default)> create table IF NOT EXISTS default.bf_1og_20150913_sa AS select ip, req_url from default.bf_1og_20150913;
#
hive (default)> show tables;
OK
tab_name
bf_1og_20150913
bf_1og_20150913_sa
#
hive (default)> select * from default.bf_1og_20150913_sa;
OK
bf_1og_20150913_sa.ip
bf_1og_20150913_sa.req_url
"27.38.5.159"
"31/Aug/2015:00:04:53
"27.38.5.159"
"31/Aug/2015:00:04:37
"27.38.5.159"
"31/Aug/2015:00:04:53
Time taken: 0.028 seconds, Fetched: 3 row(s)

4、第三种建表例子

##
hive (default)> create table IF NOT EXISTS default.bf_log_20150914 like default.bf_1og_20150913;
OK
Time taken: 0.046 seconds
##
hive (default)> show tables;
OK
tab_name
bf_1og_20150913
bf_1og_20150913_sa
bf_log
bf_log_20150914
Time taken: 0.013 seconds, Fetched: 4 row(s)
#这里是指copy表结构，不copy表数据
hive (default)> select * from default.bf_log_20150914;
OK
bf_log_20150914.ip
bf_log_20150914.user
bf_log_20150914.req_url
Time taken: 0.029 seconds

三、Create Database

DDL：https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DDL

DML：https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DML

1、Create Database

CREATE (DATABASE|SCHEMA) [IF NOT EXISTS] database_name
[COMMENT database_comment]
[LOCATION hdfs_path]
[WITH DBPROPERTIES (property_name=property_value, ...)];

具体：

##
创建
create database db_name;
create database if not exists db_name;
#标准
#指定HDFS上的存储位置
create database if not exists db_name location ‘/user/root/hive/warehouse/db_name.db’;
##
查看
show databases;
show databases like 'db_hive*';
desc database extended db_name;
##
删除
drop database db_name;
drop database db_name cascade;
drop database if exists db_name;
##
Alter Database
ALTER (DATABASE|SCHEMA) database_name SET DBPROPERTIES (property_name=property_value, ...);
-- (Note: SCHEMA added in Hive 0.14.0)
ALTER (DATABASE|SCHEMA) database_name SET OWNER [USER|ROLE] user_or_role;
-- (Note: Hive 0.13.0 and later; SCHEMA added in Hive 0.14.0)
ALTER (DATABASE|SCHEMA) database_name SET LOCATION hdfs_path; -- (Note: Hive 2.2.1, 2.4.0 and later)