单表更新
```sqlupdate tbase set nickname ='Hello TBase' where id=1;
条件表达方法
update tbase set nickname = 'Good TBase' where nickname is null;
查询结果：
select * from tbase;
id | nickname |
2 | TBase 好 |
1 | Hello TBase |
3 | Good TBase |
分布键不能更新：
update t2 set f1=1 where f2=1;
错误信息：
ERROR: Distributed column "f1" can't be updated in current version
多表关联更新
update tbase set nickname ='Good TBase' from t_appoint_col where t_appoint_col.id=tbase.id;
查询结果：
select * from tbase;
id | nickname |
2 | TBase 好 |
返回更新的数据
update tbase set nickname = nickname where id = (random()*2)::integer returning id, nickname;
返回结果：
id | nickname |
2 | TBase 好 |
多列匹配更新
update tbase set ( nickname , age ) = ( 'TBase 好' , (random()*2)::integer );
查询结果：
select * from tbase;
id | nickname | age |
1 | TBase 好 | 2 |
2 | TBase 好 | 0 |
Shard Key 不允许更新
update tbase set id=8 where id=1;
错误信息：
ERROR: Distribute column or partition column can't be updated in current version
