Question

我有以下表格：

table1
========
rpid  | fname | lname  | tu  |  fu  |  tu_id   |  start_time    


table2
========
tu_id  | tu | fu   |  start_time

我想使用table2中的匹配记录填充table1＆＃39; tu，fu和tu_id。我根据时间戳匹配它们。

UPDATE table1 
INNER JOIN table1 
ON date_trunc('hour', table1.start_time) date_trunc('hour', table2.start_time) AND table1.rpid=table2.tu 
SET  table1.tu_id= table2.tu_id, table1.fu = table2.fu, table1.tu=table2.tu;

我现在正在收到语法错误：

错误：语法错误在或附近＆＃34; INNER＆＃34; 第1行：在date_trunc上更新table1 INNER JOIN table1（＆＃39; hour＆＃39;，table1.s ...

我以前从未尝试过这样的事情，所以我确定我错过了一些明显的东西。有什么建议？

我知道INNER JOIN本身是正确的，因为我先在SELECT语句中尝试过它。它返回我想要的数据......现在我只是更新table1中的字段。谢谢。

编辑1

还试过这个：

UPDATE table1 
SET  tu_id, fu, tu FROM ( 
     SELECT table2.tu_id,  table2.fu, table2.tu 
     FROM table1, INNER JOIN table1 on date_trunc('hour', table1.start_time) = date_trunc('hour', table2.start_time) AND table1.rpid=table2.tu
);

这给了我语法错误：

ERROR:  syntax error at or near ","
LINE 1: UPDATE table1 SET  tu_id, fu, tu  FROM ( SELECT table2.t...

Answer 1

UPDATE table1 SET tu_id= table2.tu_id, fu = table2.fu, tu=table2.tu
from table2
where 
    date_trunc('hour', table1.start_time) = date_trunc('hour', table2.start_time) and table1.rpid=table2.tu 
;

Answer 2

在postgres 9.5（最后一个稳定版本）

之前，您只能使用一个选择更新多个列

所以语法如下：

9.5之前：

UPDATE table1 
SET  tu_id = (SELECT table2.tu_id 
     FROM table1
     INNER JOIN table2
        ON date_trunc('hour', table1.start_time) = date_trunc('hour', table2.start_time)
       AND table1.rpid=table2.tu),
fu = (SELECT table2.fu
     FROM table1
     INNER JOIN table2
        ON date_trunc('hour', table1.start_time) = date_trunc('hour', table2.start_time)
      AND table1.rpid=table2.tu),
tu = (SELECT table2.tu 
     FROM table1
     INNER JOIN table2
         ON date_trunc('hour', table1.start_time) = date_trunc('hour', table2.start_time)
        AND table1.rpid=table2.tu);

9.5+：

UPDATE table1 
SET  (tu_id, fu, tu) = (
  SELECT table2.tu_id,  table2.fu, table2.tu 
     FROM table1
    INNER JOIN table2
       ON date_trunc('hour', table1.start_time) = date_trunc('hour', table2.start_time)
      AND table1.rpid=table2.tu
);

编辑：我忘记了UPDATE ... FROM ...，感谢其他回复者在我的记忆中刷新它！

Answer 3

我相信这是最简单的方法：

UPDATE table1 t
SET tu_id = t2.tu_id,
    fu = t2.fu,
    tu = t2.tu
FROM  table2 t2
WHERE date_trunc('hour', t.start_time) = date_trunc('hour', t2.start_time) 
AND   t.rpid=t2.tu;

如何基于批量选择插入批量数据

3 个答案: