cassandra - cql

语法

CQL。

Datacenter

use system;
select data_center from local;

Role / User

创建

CREATE ROLE [IF NOT EXISTS] role_name 
[WITH SUPERUSER = true | false
 | LOGIN = true | false  
 | PASSWORD =  'password' 
 | OPTIONS = option_map]

示例

CREATE ROLE IF NOT EXISTS 'root' WITH SUPERUSER = true AND LOGIN = false;
CREATE ROLE IF NOT EXISTS 'root' WITH SUPERUSER = true AND PASSWORD = 'root';

修改权限

ALTER ROLE role_name 
[WITH [PASSWORD = 'password']
   [LOGIN = true | false] 
   [SUPERUSER = true | false] 
   [OPTIONS = map_literal]]

示例

ALTER ROLE root WITH PASSWORD = 'NewPassword';

Key Space

查询

# 列出所有 keysapces
desc keyspaces;

创建

CREATE  KEYSPACE [IF NOT EXISTS] keyspace_name 
   WITH REPLICATION = { 
      'class' : 'SimpleStrategy', 'replication_factor' : N } 
     | 'class' : 'NetworkTopologyStrategy', 
       'dc1_name' : N [, ...] 
   }
   [AND DURABLE_WRITES =  true|false] ;

示例

CREATE  KEYSPACE IF NOT EXISTS "trace" WITH REPLICATION = {
		'class' : 'NetworkTopologyStrategy', 
   	'vg' : 2
}

Table

查询

desc <keyspace-name>;

use <keyspace-name>;
desc tables;

创建

CREATE TABLE [IF NOT EXISTS] [keyspace_name.]table_name ( 
   column_definition [, ...]
   PRIMARY KEY (column_name [, column_name ...])
[WITH table_options
   | CLUSTERING ORDER BY (clustering_column_name order])
   | ID = 'table_hash_tag'
   | COMPACT STORAGE]

数据类型参考这里。

删除

DROP TABLE [IF EXISTS] keyspace_name.table_name

修改

添加列

ALTER TABLE [keyspace_name.] table_name 
[ALTER column_name TYPE cql_type]
[ADD (column_definition_list)]
[DROP column_list | COMPACT STORAGE ]
[RENAME column_name TO column_name]
[WITH table_properties];

示例

ALTER TABLE trace.ranker ADD rid TEXT;

Query

// 查询一条
select * from ks.table limit 1;
select * from ks.table where id='value' limit 1;