Question

所以我在MariaDB数据库中有一个表，其中有几行，如：

+----+--------+-----------+---------+-----------+
| id | faseID | fase_tipo | fase_nr | tarefa_id |
+----+--------+-----------+---------+-----------+
|  5 |      3 |         2 |       1 |         2 |
|  6 |      3 |         2 |       2 |         2 |
| 17 |      3 |         2 |       3 |         2 |
| 12 |      3 |         3 |       1 |         6 |
| 18 |      3 |         3 |       2 |         6 |
+----+--------+-----------+---------+-----------+

生成者：

SELECT id, 
       faseID, 
       fase_tipo, 
       fase_nr, 
       tarefa_id 
   FROM tarefas 
   WHERE obra = '15ID000' AND 
         faseID = '3' AND 
         tarefa_id <> '0' AND 
         tarefa_main = '2'
   ORDER BY fase_tipo ASC

我在订购此搜索结果时遇到问题，因为我希望将表格排序为：

+----+--------+-----------+---------+-----------+
| id | faseID | fase_tipo | fase_nr | tarefa_id |
+----+--------+-----------+---------+-----------+
|  5 |      3 |         2 |       1 |         2 |
|  6 |      3 |         2 |       2 |         2 |
| 12 |      3 |         3 |       1 |         6 |
| 18 |      3 |         3 |       2 |         6 |
| 17 |      3 |         2 |       3 |         2 |
+----+--------+-----------+---------+-----------+

我的意思是，使用字段tarefa_id使行显示在id行之后。在内部，它与fase_nr订购。

是否有任何定位tarefa_id = id之后显示tarefa_id的所有行？

Answer 1

看看下面的内容，它应该通过自我加入和coalesce功能为您提供所需的内容。

    with test_data as (
        select 5 as id, 3 as faseID, 2 as fase_tipo, 1 as fase_nr, 2 as tarefa_id from dual
        union all
        select 6 as id, 3 as faseID, 2 as fase_tipo, 2 as fase_nr, 2 as tarefa_id from dual
        union all
        select 12 as id, 3 as faseID, 3 as fase_tipo, 1 as fase_nr, 6 as tarefa_id from dual
        union all
        select 18 as id, 3 as faseID, 3 as fase_tipo, 2 as fase_nr, 6 as tarefa_id from dual
        union all
        select 17 as id, 3 as faseID, 2 as fase_tipo, 3 as fase_nr, 2 as tarefa_id from dual
    )
    -- This is the core you should pay attention to
    select td1.* 
    from test_data td1
    left join test_data td2 
    on td2.id = td1.tarefa_id
    order by coalesce(td2.id, td1.id), td1.id, td1.fase_nr
    --
;

当然，我在Oracle中做过这个，但总体思路应该适用。

输出：

ID|FASEID|FASE_TIPO|FASE_NR|TAREFA_ID
--+------+---------+-------+---------
 5|     3|        2|      1|        2
 6|     3|        2|      2|        2
12|     3|        3|      1|        6
18|     3|        3|      2|        6
17|     3|        2|      3|        2

如果您的列不是数字类型，则需要在order by子句中对其进行转换以进行排序：

with test_data as (
    select '12' as id, '3' as faseID, '3' as fase_tipo, '1' as fase_nr, '6' as tarefa_id from dual
    union all
    select '5' as id, '3' as faseID, '2' as fase_tipo, '1' as fase_nr, '2' as tarefa_id from dual
    union all
    select '18' as id, '3' as faseID, '3' as fase_tipo, '2' as fase_nr, '6' as tarefa_id from dual
    union all
    select '6' as id, '3' as faseID, '2' as fase_tipo, '2' as fase_nr, '2' as tarefa_id from dual
    union all
    select '17' as id, '3' as faseID, '2' as fase_tipo, '3' as fase_nr, '2' as tarefa_id from dual
)
-- This is the core you should pay attention to
select td1.* 
from test_data td1
left join test_data td2 
on td2.id = td1.tarefa_id
order by to_number(coalesce(td2.id, td1.id)), to_number(td1.id), to_number(td1.fase_nr)
--
;

使用id参数排序行

1 个答案: