//创建数据库
CREATE DATEBASE IF NOT EXISTS userdb
或
CREATE SCHEMA userdb
//查看数据库
SHOW DATEBASES
//删除数据库
DROP DATEBASE IF EXISTS userdb
//创建数据库表
CREATE [TEMPORARY] [EXTERNAL] TALE [IF NOT EXISTS] [db_name] table_name
[(col_name data_type[COMMENT col_comment]...)]
[COMMENT table_comment]
[ROW FORMAT row_format]
[STORED AS file_format]
例如：
CREATE TABLE IF NOT EXISTS employee ( eid int, name String,
salary String, destination String)
COMMENT ‘Employee details’ //注释
ROW FORMAT DELIMITED //行格式字段
FIELDS TERMINATED BY ‘ ’ //字段终止符
LINES TERMINATED BY ‘
’ //行终止符
STORED AS TEXTFILE; //保存的文件类型
//插入数据
LOAD DATA [LOCAL] INPATH filepath [OVERWRITE] INTO TABLE tablename
[PARTITION (partcol1=val1, partcol2=val2 ...)]
例如：
在/home/user目录中名为sample.txt的文件。
1201 Gopal 45000 Technical manager
1202 Manisha 45000 Proof reader
1203 Masthanvali 40000 Technical writer
1204 Kiran 40000 Hr Admin
1205 Kranthi 30000 Op Admin
查询加载给定文本插入表中
LOAD DATA LOCAL INPATH /home/user/sample.txt
OVERWRITE INTO TABLE employee;
//修改表
ALTER TABLE name RENAME TO new_name
ALTER TABLE name ADD COLUMNS (col_spec[, col_spec ...])
ALTER TABLE name DROP [COLUMN] column_name
ALTER TABLE name CHANGE column_name new_name new_type
ALTER TABLE name REPLACE COLUMNS (col_spec[, col_spec ...])
//删除表
DROP TABLE [IF EXISTS] table_name;
//添加分区表
ALTER TABLE table_name ADD [IF NOT EXISTS] PARTITION partition_spec
[LOCATION location1] partition_spec [LOCATION location2] ...;
partition_spec:
: (p_column = p_col_value, p_column = p_col_value, ...)
//重命名分区
ALTER TABLE table_name PARTITION partition_spec RENAME TO PARTITION partition_spec;
//删除分区
ALTER TABLE table_name DROP [IF EXISTS] PARTITION partition_spec, PARTITION partition_spec,...;
//
