Hive：DCL(库表结构)

表创建：1.create   2.文件导入  3.creat + select

方式一：create

• create table 表名(字段1 类型,字段2 类型,...,字段n 类型,) row format delimited fields terminated by '\t';
  ------------------------------------------------------
  create table user_info(id bigint, account string, name string) row format delimited fields terminated by '\t'; 

方式二： 文件导入 

• load data local inpath '/路径/../文件名(尽量=表名)' into table 表名;
  --------------------------------------------------
  load data local inpath '/home/hadoop/data/user_info' into table user_info;   
  
  ------------------------------------------------------------------------
  load data inpath '路径/表文件' into table 表名 partition (分区名)
  ----------------------
  load data inpath '/outout/p*' into table tbl2 partition (logdate='2020-12'); 

方式三：creat + select

• create table 表名 row format delimited fields terminated by '\t' 
  as
  	select 基表(字段列表 )
      from  基表
  	[where 条件]
  	[join  基表2] 
  	[on    条件]  ;
  ----------------------------------
  create table result row format delimited fields terminated by '\t' 
  as
  	select t1.account, t1.income, t1.surplus, t2.name 
  	from user_info t2 
  	join 
  		(select account, sum(income) as income, sum(income-expenses) as surplus 
  		from trade_detail 
  		group by account) t1 
  	on(t1.account = t2.account);
  ---------------------------------------------------------
  create table pv row format delimited fields terminated by '\t' 
  as 
      select count(*) from logs where date='2020-12-25';

创建 外部表

• create external table 表名(字段名 字段类型...列表) 
  partitioned by (分区字段 字段类型) 
  row format delimited fields terminated by '\t' 
  location '存放路径';
  ----------------------
  create external table t_detail(id bigint, account string, income double,time string) 
  partitioned by (logdate string) 
  row format delimited fields terminated by '\t' 
  location '/hive/mytb_partition';

分区创建和修改

分区添加或删除

• alter table 表名 add/delete partition (分区信息) location '/路径/文件夹名==分区
  --------------------
  alter table daxiang add partition (nation='in') location '/hive/daxiang/nation=in'