错误 SQL 状态：42P01 在 postgres 中

Question

我有这么大的 select 我认为是正确的，我必须执行但我不知道为什么它给我一个错误。我所有的表都是单表，它们之间没有任何关系。知道会发生什么吗？发生在第二个ON时：

select DISTINCT t0_0.id_pord, t0_0.prod_fam, t0_0.prod_nam, t0_0.prod_mod  
from inventory t0_0 
INNER JOIN ( select DISTINCT c0.id_dev 
             FROM ps_det c0 
             INNER JOIN ( select DISTINCT c0.id_dev 
                          FROM ps_det c0 
                          INNER JOIN mtx_det c1 
                            ON c0.psirtid = c1.alert_id  ) t4_0 
               ON t0_0.id_dev = t3_0.id_dev
             WHERE c0.invent = '1333' 
             AND c0.cust = '598' ) t3_0 
  ON t0_0.id_dev = t3_0.id_dev  
where  t0_0.prod_fam IN ('Cisco', 'Catalyst', '3750 Series') 
AND t0_0.invent ='1333'
AND t0_0.cust = '598'

它给了我那个错误：

ERROR:  invalid reference to FROM-clause entry for table "t0_0"
LINE 1: mtx_det c1 ON c0.psirtid = c1.alert_id) t4_0 ON t0_0.id_dev...
                                                             ^
HINT:  There is an entry for table "t0_0", but it cannot be referenced from this part of the query.
********** Error **********

ERROR: invalid reference to FROM-clause entry for table "t0_0"
SQL state: 42P01
Hint: There is an entry for table "t0_0", but it cannot be referenced from this part of the query.
Character: 352

有什么想法吗？

Answer 1

您从一个子查询中引用了 t0_0：

select DISTINCT c0.id_dev 
FROM ps_det c0 
INNER JOIN ( select DISTINCT c0.id_dev 
             FROM ps_det c0 
             INNER JOIN mtx_det c1 
               ON c0.psirtid = c1.alert_id  ) t4_0 
  ON t0_0.id_dev = t3_0.id_dev -- HERE'S YOUR PROBLEM
WHERE c0.invent = '1333' 
             AND c0.cust = '598'

每个子查询必须包含自己的别名，所以子查询应该是：

select DISTINCT c0.id_dev 
FROM ps_det c0 
INNER JOIN ( select DISTINCT c0.id_dev 
             FROM ps_det c0 
             INNER JOIN mtx_det c1 
               ON c0.psirtid = c1.alert_id  ) t4_0 
  ON t4_0.id_dev = c0.id_dev -- HERE'S THE FIX
WHERE c0.invent = '1333' 
             AND c0.cust = '598'

错误 SQL 状态：42P01 在 postgres 中

Error SQL state: 42P01 In postgres

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