UNION类型不匹配

Question

当我在查询下运行时，出现此错误

UNION类型的text和bigint无法匹配

SELECT 
    1 AS STEP
  , '' AS ProviderName
  , '' AS Procedurecode
  , Claimid
  , Patient_First_Name
  , Patient_Last_Name
  , DOS
  , SUM(COALESCE(Total_Charge,0))
  , SUM(COALESCE(PaidAmount,0))
  , PostedDate
  , CheckEFTDate
  , CheckEFTNo 
FROM table_name
GROUP BY ProviderName, Claimid, Patient_First_Name, Patient_Last_Name, DOS, PostedDate,
         CheckEFTDate, CheckEFTNo
UNION ALL
SELECT 
    2 AS STEP
  , '' AS ProviderName
  , '' AS Procedurecode
  , COUNT(Claimid)
  , '' AS Patient_First_Name
  , '' AS Patient_Last_Name
  , NULL::date AS DOS
  , SUM(COALESCE(Total_Charge,0))
  , SUM(COALESCE(PaidAmount,0))
  , NULL::date AS PostedDate
  , NULL::date AS CheckEFTDate
  , '' AS CheckEFTNo 
FROM table_name
GROUP BY Claimid

Answer 1

我的错误是，列的并集名称无关紧要，但是顺序却很重要（也许我错了，我找不到文档）

例：

1）很好

select
1 :: integer as someint, 
'1' :: text as sometext

union

select
2 :: integer as someint,
'2' :: text as sometext

退货

someint sometext
1   1   1
2   2   2

2）这不好

select
1 :: integer as someint, 
'1' :: text as sometext

union

select
'2' :: text as sometext,
2 :: integer as someint

抛出

Error(s), warning(s):

42804: UNION types integer and text cannot be matched

尝试一下https://rextester.com/l/postgresql_online_compiler

Answer 2

最有可能的是 - 尽管无法确定，因为您还没有发布表定义 - 该字段claimid的类型为text（或varchar，但这都是相同的），count(claimid)同时生成bigint. 在这种情况下，快速解决办法就是执行count(claimid)::text.

否则就不清楚你想要实现什么。在顶部选择中，您显然想要对每个患者的费用和支付金额进行求和。底部的选择应该将所有患者的费用和支付金额相加？您不应该尝试在单个查询中组合这些不同的内容。最好有两个不同的查询，它们具有明显的功能，并且不依赖于诸如 之类的限定符的知识step。