Question

我有三个表（deb，dos，char），我正在寻找一个SQL查询来获取result表，如下所示：

table: deb
+----+-------------+--------+
| id | label       | dos_id |
+----+-------------+--------+
|  1 | right       |      1 | 
|  2 | left        |      2 | 
+----+-------------+--------+

table:char
+----+-------------+--------+
| id | name        | dos_id |
+----+-------------+--------+
|  1 | jack        |      1 | 
|  2 | thaw        |      1 |
|  3 | lbaz        |      2 |
|  4 | amar        |      3 |
+----+-------------+--------+

table:dos
+----+-------------+
| id | color       |
+----+-------------+
|  1 | black       | 
|  2 | white       |
+----+-------------+


result table
+----+-------------+--------+
| id | color       | value  |
+----+-------------+--------+
|  1 | black       |  right | 
|  1 | black       |  jack  |
|  1 | black       |  thaw  |
|  2 | white       |  left  |
|  2 | white       |  lbaz  |
|  2 | white       |  amar  |
+----+-------------+--------+

我尝试左右加入，但它没有用。

我正在寻找的是，对于每个dos行，我在其他列中得到相应的char和deb值。

也许在一个行中选择查询可能有所帮助。我不知道。

请帮帮我，谢谢。

Answer 1

您需要运行2个单独的查询，并将结果组合到一个结果集中。您可以使用UNION运算符执行此操作，如下所示：

SELECT * FROM 
(
  SELECT dos.id id, dos.color color, deb.label value
  FROM dos INNER JOIN deb on dos.id = deb.dos_id
  UNION
  SELECT dos.id id, dos.color color, char.name value
  FROM dos INNER JOIN char on dos.id = char.dos_id
)
ORDER BY id

编辑：

SELECT * 
FROM 
( 
  SELECT dos.id AS id, dos.date_facture AS facture, deb.libelle AS lbl, '' AS nom
  AS lbl FROM jos_tktransit_dossier dos INNER JOIN jos_tktransit_deboure deb ON dos.id = deb.id_dossier 
  UNION 
  SELECT dos.id AS id, dos.date_facture AS facture, '' AS lbl, charg.nom_charge AS nom 
  FROM jos_tktransit_dossier dos INNER JOIN jos_tktransit_charge_assistance charg ON dos.id = charg.id_dossier 
)

Answer 2

可能是这样的：

SELECT dos.id, color, deb.label as value  FROM dos, deb WHERE dos_id = dos.id
UNION SELECT dos.id, color, char.name as value FROM dos, char WHERE dos_id = dos.id;

Answer 3

尝试以下方法：

(select d.id,d.color,c.name from dos d , char1 c where d.id=c.dos_id) union (select d.id,d.color,e.label from dos d, deb e where d.id= e.dos_id)

这应该输出以下内容：

ID  COLOR   NAME
1   black   jack
1   black   right
1   black   thaw
2   white   lbaz
2   white   left

...但它没有按照正确的顺序显示值：

+----+-------------+--------+
| id | color       | value  |
+----+-------------+--------+
|  1 | black       |  right | 
|  1 | black       |  jack  |
|  1 | black       |  thaw  |
|  2 | white       |  left  |
|  2 | white       |  lbaz  |
| *2 | white       |  amar* |
+----+-------------+--------+

如何将多个表连接到一个MySQL？

3 个答案: