Apache Doris 系列： 基础篇-单独更新一列

数据模型选择

数据表使用 Aggregate 聚合模型
需要更新的字段使用关键字 REPLACE_IF_NOT_NULL

举例

建表

CREATE TABLE IF NOT EXISTS test.expamle_tbl2
(
    `user_id` LARGEINT NOT NULL COMMENT "用户id",
    `date` DATE NOT NULL COMMENT "数据灌入日期时间",
    `city` VARCHAR(20) COMMENT "用户所在城市",
    `age` SMALLINT COMMENT "用户年龄",
    `sex` TINYINT COMMENT "用户性别",
    `last_visit_date` DATETIME REPLACE_IF_NOT_NULL COMMENT "用户最后一次访问时间",
    `cost` BIGINT REPLACE_IF_NOT_NULL COMMENT "用户总消费",
    `max_dwell_time` INT REPLACE_IF_NOT_NULL COMMENT "用户最大停留时间",
    `min_dwell_time` INT REPLACE_IF_NOT_NULL COMMENT "用户最小停留时间"
)
AGGREGATE KEY(`user_id`, `date`, `city`, `age`, `sex`)
DISTRIBUTED BY HASH(`user_id`) BUCKETS 1
PROPERTIES (
"replication_allocation" = "tag.location.default: 1"
);

插入数据

mysql> insert into test.expamle_tbl2 values(10000,'2017-10-01','北京',20,0,'017-10-01 06:00:00',20,10,10);

mysql> select * from test.expamle_tbl2
    -> ;
+---------+------------+--------+------+------+---------------------+------+----------------+----------------+
| user_id | date       | city   | age  | sex  | last_visit_date     | cost | max_dwell_time | min_dwell_time |
+---------+------------+--------+------+------+---------------------+------+----------------+----------------+
| 10000   | 2017-10-01 | 北京   |   20 |    0 | 0017-10-01 06:00:00 |   20 |             10 |             10 |
+---------+------------+--------+------+------+---------------------+------+----------------+----------------+
1 row in set (0.00 sec)

更新cost字段

mysql> insert into test.expamle_tbl2 (user_id,date,city,age,sex,cost) values(10000,'2017-10-01','北京',20,0,50);

mysql> select * from test.expamle_tbl2
    -> ;
+---------+------------+--------+------+------+---------------------+------+----------------+----------------+
| user_id | date       | city   | age  | sex  | last_visit_date     | cost | max_dwell_time | min_dwell_time |
+---------+------------+--------+------+------+---------------------+------+----------------+----------------+
| 10000   | 2017-10-01 | 北京   |   20 |    0 | 0017-10-01 06:00:00 |   50 |             10 |             10 |
+---------+------------+--------+------+------+---------------------+------+----------------+----------------+
1 row in set (0.00 sec)

注意：user_id, date, city, age, sex 这几个字段是聚合键，必须要指定

应用场景举例

在数仓构建大宽表的场景中， 当上游任一来源表产生延迟，均会造成大宽表延迟，进而导致整体宽表数据时效性下降。
单独更新一列的功能可解决上游数据更新延迟导致整个宽表延迟的问题，进而提升了数据的时效性。