Question

我收到错误“将nvarchar值'23,24,3,45,91'转换为数据类型int时转换失败。” ON子句似乎发生了错误。 E.ID是整数字段，而F.LegalIssue是由逗号分隔的整数的varchar字段。下面是带有该错误的代码。

SELECT F.[FDTitle], E.PrimaryOpID as [FD Primary OP ID], F.County as [FD County], F.Status as [FD Status], F.IssueDate as [FD Date]
FROM [dbo].[tbl_FinalDetMain] F
LEFT OUTER JOIN [dbo].[tbl_lk_Exemptions_FD] E ON E.ID = F.LegalIssue
WHERE F.[FDNbr] = '2013-0041'

我已经尝试了下面的代码用于on子句，但它只返回一个整数值，而不是整个整数字符串。

E.ID = cast(LEFT(F.LegalIssue,PATINDEX('%[^0-9]%',F.LegalIssue)-1) as int)

结果应包括由逗号分隔的五个整数。

Answer 1

如果LegalIssue包含逗号分隔的数字字符串，那么您真的需要一个关联表。缺乏这一点，这是一种方便（但不是有效）的方式来进行连接：

SELECT F.[FDTitle], E.PrimaryOpID as [FD Primary OP ID], F.County as [FD County],
       F.Status as [FD Status], F.IssueDate as [FD Date]
FROM [dbo].[tbl_FinalDetMain] F LEFT OUTER JOIN
      [dbo].[tbl_lk_Exemptions_FD] E
      ON ','+F.LegalIssue+',' like '%,'cast(E.ID as varchar(255))+',%'
WHERE F.[FDNbr] = '2013-0041';

这会以逗号为前缀和后缀，以避免冲突，例如在“1,100,1000”中找到“10”。

Answer 2

使用xml数据类型，您可以将字符串分解为这样的整数。用户定义函数的良好候选者我会说： - ）

declare @test varchar(max)

set @test = '1,2,3,4,5'

select 
     T2.item.value('(./text())[1]','int') 
from
     (select convert(xml,'<items><t>'+replace(@test,',','</t><t>')+'</t></items>') as xmldoc)
as xmltable
     CROSS APPLY xmltable.xmldoc.nodes('/items/t') as T2(item)

Answer 3

您必须将F.LegalIssue标准化为多行，否则您将不得不使用LIKE

像

这样的东西

    CAST(E.ID A VARCHAR(50)) = F.LegalIssue
OR  F.LegalIssue LIKE CAST(E.ID A VARCHAR(50)) + ',%'
OR  '%,' + F.LegalIssue LIKE CAST(E.ID A VARCHAR(50)) + ',%'
OR  '%,' + F.LegalIssue LIKE CAST(E.ID A VARCHAR(50))

如您所见，表的实际设计是个问题。您应该避免使用当前的设计，并选择1 to many或many to many设计。

以下是如何使用递归CTE展平值的演示

SQL Fiddle DEMO

创建测试表和数据

CREATE TABLE Tada(
  ID INT,
  SomeCommaString VARCHAR(50)
  )
INSERT INTO Tada Values (1, '10'),(2,'5,6,12,16')

展平桌子

;WITH Vals AS (
  SELECT 
      ID,
      CASE
          WHEN CHARINDEX(',',SomeCommaString) = 0
            THEN SomeCommaString
          WHEN CHARINDEX(',',SomeCommaString) > 0
            THEN LEFT(SomeCommaString,CHARINDEX(',',SomeCommaString) - 1)
      END Val,

      CASE
          WHEN CHARINDEX(',',SomeCommaString) > 0
            THEN RIGHT(SomeCommaString,LEN(SomeCommaString) - CHARINDEX(',',SomeCommaString))
          ELSE NULL
      END Remainder
  FROM Tada
  UNION ALL
  SELECT 
      ID,
      CASE
          WHEN CHARINDEX(',',Remainder) = 0
            THEN Remainder
          WHEN CHARINDEX(',',Remainder) > 0
            THEN LEFT(Remainder,CHARINDEX(',',Remainder) - 1)
      END Val,

      CASE
          WHEN CHARINDEX(',',Remainder) > 0
            THEN RIGHT(Remainder,LEN(Remainder) - CHARINDEX(',',Remainder))
          ELSE NULL
      END Remainder

  FROM Vals
  WHERE Remainder IS NOT NULL
)
SELECT ID, Val
FROM Vals

T-SQL如何将逗号分隔的数字字符串转换为整数

3 个答案:

SQL Fiddle DEMO