Postgresql-仅当

我正在寻找一种方法来连接Id上的两列。 Table2 id有重复的id。我需要过滤id，其中test有一个最小值和关联的test2，但删除其余的。 当我使用内部连接和左连接时，我在测试中得到了多个ID

Sample data
Table1

        +----+--------+-----+
        | Id | weight | seq |
        +----+--------+-----+
        | 58 | 180    | 34  |
        +----+--------+-----+
        | 36 | 139    | 33  |
        +----+--------+-----+
        | 53 | 150    | 91  |
        +----+--------+-----+

Table2
+----+------+-------+
| Id | test | test2 |
+----+------+-------+
| 58 | 90   | 12    |
+----+------+-------+
| 36 | 45   | 19    |
+----+------+-------+
| 36 | 23   | 24    |
+----+------+-------+
| 53 | 20   | 22    |
+----+------+-------+

期望输出

+----+--------+-----+------+-------+
| Id | weight | seq | test | test2 |
+----+--------+-----+------+-------+
| 58 | 180    | 34  | 90   | 12    |
+----+--------+-----+------+-------+
| 36 | 139    | 33  | 23   | 24    |
+----+--------+-----+------+-------+
| 53 | 150    | 91  | 20   | 22    |
+----+--------+-----+------+-------+

 SELECT
    table1.id, 
    table1.weight, 
    table1.seq, 
    table2.id, 
    table2.test, 
    table2.test2
    FROM 
    public.table1
    LEFT JOIN public.table2 
    ON table1.id = table2.id;

SELECT 
table1.id, 
table1.weight, 
table1.seq, 
table2.id, 
table2.test, 
table2.test2
FROM 
public.table1
INNER JOIN public.table2 
ON table1.id = table2.id;

我的输出

+-----------------------------+
| ID Weight seq id test test2 |
+-----------------------------+
|   36  139   33  36  45   19 |
|   36  139   33  36  23   24 |
|   53  150   91  53  20   23 |
|   58  180   34  58  90   12 |
+-----------------------------+

---

您可以使用

row\u number（）

窗口函数获取具有最小

test

值的行：

SELECT t1.*
FROM   table1 t1
JOIN   (SELECT id, test, test2, RANK() OVER (PARTITION BY id ORDER BY test ASC) rk
        FROM   table2) t2 ON t1.id = t2.id AND rk = 1

---

请张贴已尝试到现在请更新在您的question@Kul你可以用你的问题来添加更多的信息——这比一系列评论更容易阅读