sql - postgres 在冲突错误时插入 - 没有唯一或排除约束

Question

我在 postgres 中有两个表 daily_report和 summary_songs .

用于创建表的 Sql 文件在这里:https://nofile.io/f/Ef94rMFRh6C/file.sql

我要更新summary_songs在每天结束时，条件如下:

如果userid已经不存在，则从daily_report记录需要插入summary_songs

如果userid存在，则 summary_songs.countid = summary_songs.countid+ daily_report.countid .

我使用以下查询来更新 summary_songs :

insert into summary_songs 
(select * from daily_report as B)
on conflict (userid, songd) 
do update set countid = countid+excluded.countid ;  

我得到以下错误:

ERROR: there is no unique or exclusion constraint matching the ON CONFLICT specification

Answer 1

使用 on conflict您需要强制执行 unique(userid, songd)在您的 summary_songs table :

SQL Fiddle

PostgreSQL 9.6 架构设置 :

CREATE TABLE summary_songs (
    date_time date  NOT NULL,
    userid integer NOT NULL,
    songd integer NOT NULL,
    countid integer NOT NULL,
    unique(userid, songd) 
);


CREATE TABLE daily_report(
    date_time date NOT NULL,
    userid integer NOT NULL,
    songd integer NOT NULL,
    countid integer NOT NULL
);


insert into daily_report (date_time, userid, songd, countid) values
(to_date('2017-12-31','YYYY-MM-DD'),  1 ,     1 ,       5),
(to_date('2017-12-31','YYYY-MM-DD'),  2 ,     1 ,      10),
(to_date('2017-12-31','YYYY-MM-DD'),  4 ,     1 ,       7);


insert into summary_songs (date_time, userid, songd, countid) values
(to_date('2017-12-30', 'YYYY-MM-DD'),1, 1,  80),
(to_date('2017-12-30', 'YYYY-MM-DD'),2, 1,  51),
(to_date('2017-12-30', 'YYYY-MM-DD'),3, 1,  66);

查询 1 :

select * from daily_report 

Results :

|  date_time | userid | songd | countid |
|------------|--------|-------|---------|
| 2017-12-31 |      1 |     1 |       5 |
| 2017-12-31 |      2 |     1 |      10 |
| 2017-12-31 |      4 |     1 |       7 |

查询 2 :

select * from summary_songs 

Results :

|  date_time | userid | songd | countid |
|------------|--------|-------|---------|
| 2017-12-30 |      1 |     1 |      80 |
| 2017-12-30 |      2 |     1 |      51 |
| 2017-12-30 |      3 |     1 |      66 |

查询 3 :

insert into summary_songs (date_time, userid, songd, countid)
select date_time, userid, songd, countid from daily_report
on conflict (userid, songd) 
do update set 
  countid = summary_songs.countid + excluded.countid ,
  date_time = excluded.date_time

查询 4 ​​ :

select * from summary_songs 

Results :

|  date_time | userid | songd | countid |
|------------|--------|-------|---------|
| 2017-12-30 |      3 |     1 |      66 |
| 2017-12-31 |      1 |     1 |      85 |
| 2017-12-31 |      2 |     1 |      61 |
| 2017-12-31 |      4 |     1 |       7 |