Question

我有一个包含user_id，skill的表格。

user_id  skill
1         foo
1         bar
2         foo
3         bar

我们可以根据他的 bar 技能为user 1提供工作。

如果收到的新要约也需要栏技能，我想将其委托给具有该技能的下一个用户。

如果找不到合格用户，则从表顶部查询以查找具有该技能的用户。

另一个名为jobs的表记录了所有作业history.its列是id，user_id，skill和timestamps

Answer 1

这是不完整的，但应该提供一些思考的食物......

DROP TABLE IF EXISTS user_skill;

CREATE TABLE user_skill
(user_id  INT NOT NULL
,skill_id INT NOT NULL
,PRIMARY KEY(user_id,skill_id)
);

INSERT INTO user_skill VALUES
(1,101),
(1,102),
(2,101),
(3,103);

DROP TABLE IF EXISTS jobs;

CREATE TABLE jobs
(job_id INT NOT NULL PRIMARY KEY
,skill_id INT NOT NULL
,assigned_to INT NULL
);

INSERT INTO jobs VALUES
(1001,101,1),
(1002,103,NULL),
(1003,102,NULL),
(1004,101,NULL);

UPDATE jobs x 
  JOIN
     ( SELECT u.*
            , us.skill_id
            , unassigned.job_id
         FROM user u 
         JOIN user_skill us 
           ON us.user_id = u.user_id 
         LEFT 
         JOIN jobs assigned  
           ON assigned.assigned_to = u.user_id 
         JOIN jobs unassigned 
           ON unassigned.skill_id = us.skill_id 
        WHERE unassigned.assigned_to IS NULL 
        ORDER 
           BY assigned.job_id IS NULL DESC
            , assigned.job_id DESC LIMIT 1
     ) y
    ON y.skill_id = x.skill_id
   AND y.job_id = x.job_id
   SET x.assigned_to = y.user_id;

来自给定行的Mysql循环查询

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