Oracle 12C SQL - 使用联接填充缺失的结果答案

【问题标题】：Oracle 12C SQL - Populate missing results with JoinsOracle 12C SQL - 使用联接填充缺失的结果
【发布时间】：2020-12-06 10:32:03
【问题描述】：

我有以下数据表（例如简化）

TEAM    WORKS   TT
TEAM_A  JOB_1   10
TEAM_A  JOB_3   20
TEAM_B  JOB_2   30

我希望得到以下结果

TEAM    WORKS   TT
TEAM_A  JOB_1   10
TEAM_A  JOB_2   NULL
TEAM_A  JOB_3   20
TEAM_B  JOB_1   NULL
TEAM_B  JOB_2   30
TEAM_B  JOB_3   NULL

这个结果表需要为每个团队添加原始数据集中没有出现的工作类型，并给出时间值NULL

我尝试了以下 SQL，并尝试了许多连接类型，但始终无法获得我想要的结果。

WITH BASE AS (
            SELECT 'TEAM_A' AS TEAM, 'JOB_1' AS WORKS, 10 AS TT FROM DUAL
UNION ALL   SELECT 'TEAM_A' AS TEAM, 'JOB_3' AS WORKS, 20 AS TT FROM DUAL
UNION ALL   SELECT 'TEAM_B' AS TEAM, 'JOB_2' AS WORKS, 30 AS TT FROM DUAL
)
SELECT
        BASE.TEAM
    ,   BASE.WORKS
    ,   BASE.TT
FROM BASE
FULL OUTER JOIN (
                SELECT 'JOB_1' AS WORKS FROM DUAL
    UNION ALL   SELECT 'JOB_2' AS WORKS FROM DUAL
    UNION ALL   SELECT 'JOB_3' AS WORKS FROM DUAL
) WORK_TYPES ON BASE.WORKS = WORK_TYPES.WORKS
;

【问题讨论】：

交叉加入团队和工作价值观。外部联接。
jarlh，你有例子吗？当我交叉加入时，它仍然给我不正确的结果。
partitioned outer join 正是为此类任务而创建的。

标签： sql oracle join left-join oracle12c

【解决方案1】：

您可以交叉加入不同的团队和作品，然后带上left join：

select te.team, wo.work, ta.tt
from (select distinct team from mytable) te
cross join (select distinct work from mytable) wo
left join mytable ta
    on ta.team = te.team and ta.work = wo.work
order by te.team, wo.work

【讨论】：

【解决方案2】：

显而易见的解决方案是使用partitioned outer join，这正是你的问题：

WITH BASE AS (
            SELECT 'TEAM_A' AS TEAM, 'JOB_1' AS WORKS, 10 AS TT FROM DUAL
UNION ALL   SELECT 'TEAM_A' AS TEAM, 'JOB_3' AS WORKS, 20 AS TT FROM DUAL
UNION ALL   SELECT 'TEAM_B' AS TEAM, 'JOB_2' AS WORKS, 30 AS TT FROM DUAL
)
SELECT
        BASE.TEAM
    ,   WORK_TYPES.WORKS
    ,   BASE.TT
FROM (
                      SELECT 'JOB_1' AS WORKS FROM DUAL
          UNION ALL   SELECT 'JOB_2' AS WORKS FROM DUAL
          UNION ALL   SELECT 'JOB_3' AS WORKS FROM DUAL
     ) WORK_TYPES 
     left JOIN BASE
     partition by (base.team)
     ON BASE.WORKS = WORK_TYPES.WORKS
;

结果：

TEAM   WORKS         TT
------ ----- ----------
TEAM_A JOB_1         10
TEAM_A JOB_2
TEAM_A JOB_3         20
TEAM_B JOB_1
TEAM_B JOB_2         30
TEAM_B JOB_3

【讨论】：