clickhouse基本操作_clickhouse rename

1.新增

insert into tableName field1,field2,... values(value1,value2,...);

2.删除

alter table tableName delete where 1=1;

删除一定要带where条件

3.修改

alter table tableName update field1='value' where field1='orgValue'

4.查询

select field1,field2 from tableName where field1=2;

5.新增字段

alter table tableName add column `columnName`  字段类型;

6.删除字段

alter table tableName drop column `columnName` ;

7.表重命名

rename table A to B

8.修改字段类型(慎用Nullable)

alter table tableName MODIFY COLUMN fieldName 字段类型;

9.创建TTL

   已存在表添加TTL

   alter table tableName modify TTL create_date + INTERVAL +1 DAY

   创建表时增加TTL

  CREATE TABLE example_table (

        `event_date` Date,

        `uid` Int32,

        `name` String

)

ENGINE = ReplicatedAggregatingMergeTree('/clickhouse/tables/{shard}/example_table', '{replica}')

PARTITION BY event_date

ORDER BY uid

TTL event_date + toIntervalMonth(1)

SETTINGS index_granularity = 128;

# 修改表的 TTL，event_date超过三个月的数据自动删除

ALTER TABLE example_table MODIFY TTL event_date + toIntervalMonth(3);

10.删除分区

alter table 表名 drop partition partitionName;

 分区查询：

select * from system.parts p where table = '表名'

11.添加注释

ALTER TABLE tableName COMMENT COLUMN columnName '注释信息';