show databases ;-- 创建数据库  相当于新增一个 目录
create database test_db1;
-- 删除数据库   相当于删除一个目录
drop database test_db1;use test_db;
show tables ;
create table helloword(id int,name string) row format delimited fields terminated by ',';
create table sex(id int,name string) row format delimited fields terminated by ',';drop table helloword;-- 需要将文件放到hive所在服务器
load data local inpath '/usr/local/src/test/测试文件.txt' overwrite into table helloword;
load data local inpath '/usr/local/src/test/join测试.txt' overwrite into table sex;
-- '/usr/local/src/test/测试文件.txt': 如果不是本地导入可以指定从hdfs中导入
load data inpath 'hdfs://localhost:8020/data/测试.txt' overwrite into table sex;
-- overwrite 是否覆盖show tables ;
select * from helloword;
select count(*) from helloword;
select * from helloword where id = 1;
-- 测试join
select * from sex;
select a.id, a.name,s.name from helloword a left join sex s on a.id = s.id;-- group by 分组   having 分组情况条件筛选
select count(id) from helloword group by id having id = 1;-- 不同数据类型
create external table t2(id      int,name    string,hobby   array<string>,add     map<String,string>
)
row format delimited
fields terminated by ','
collection items terminated by '-'
map keys terminated by ':'
location '/user/t2'
;-- 查表法建表 将数据  和  表结构一起 复制
create table t3 as
selectid,name
from t2
;--  like 建表  只会复制 表结构   数据为空
create table t4 like t2;