需要SQL触发器根据破折号分隔符拆分字符串

Question

我正在寻找MSSQL 2005触发器的正确​​语法，该触发器将拆分一列的值并更新其他四列。

• 数据库：TestDB
• 表：UploadAppTable

之前

|OriginalFile     | EmployeeID | EmployeeTitle | Location | ApplicationID 
|0146291-ITDCCT-02-1367413404 |   |    |   | 

我需要什么，如果以下。当新记录被插入时，我需要SQL触发器来更新表格。

输出

|OriginalFile     | EmployeeID | EmployeeTitle | Location | ApplicationID 
|0146291-ITDCCT-02-1367413404 | 0146291 | ITDCCT  | 02  | 1367413404 

任何帮助将不胜感激。

Answer 1

分隔这些值可以使用dbo.SplitStrings_CTE功能

CREATE FUNCTION dbo.SplitStrings_CTE(@List nvarchar(max), @Delimiter nvarchar(1)) 
RETURNS @returns TABLE(val nvarchar(max), [level] int, PRIMARY KEY CLUSTERED([level])) 
AS 
BEGIN 
;WITH cte AS 
(
    SELECT SUBSTRING(@List, 0, CHARINDEX(@Delimiter, @List)) AS val, 
     CAST(STUFF (@List + @Delimiter, 1, CHARINDEX(@Delimiter, @List), '') AS nvarchar(max)) AS stval, 
     1 AS [level] 
    UNION ALL 
    SELECT SUBSTRING(stval, 0, CHARINDEX(@Delimiter, stval)), 
     CAST(STUFF (stval, 1, CHARINDEX(@Delimiter, stval), '') AS nvarchar(max)), 
     [level] + 1 
    FROM cte 
    WHERE stval != '' 
) 
    INSERT @returns 
    SELECT REPLACE(val, ' ', '') AS val, [level] 
    FROM cte 
    RETURN 
END 

创建功能后，使用UPDATE语句

;WITH cte AS 
( 
    SELECT t.OriginalFile, t.EmployeeID, t.EmployeeTitle, t.Location, t.ApplicationID, 
     NewEmployeeID = MAX(CASE WHEN o.level = 1 THEN o.val END) OVER(), 
     NewEmployeeTitle = MAX(CASE WHEN o.level = 2 THEN o.val END) OVER(), 
     NewLocation = MAX(CASE WHEN o.level = 3 THEN o.val END) OVER(), 
     NewApplicationID = MAX(CASE WHEN o.level = 4 THEN o.val END) OVER() 
    FROM dbo.UploadAppTable t CROSS APPLY dbo.SplitStrings_CTE(t.OriginalFile, '-') o 
) 
    UPDATE cte 
    SET EmployeeID = NewEmployeeID, 
     EmployeeTitle = NewEmployeeTitle, 
     Location = NewLocation, 
     ApplicationID = NewApplicationID 

演示上SQLFiddle

或UPDATE语句的多重更新

;WITH cte AS 
( 
    SELECT t.OriginalFile, t.EmployeeID, t.EmployeeTitle, t.Location, t.ApplicationID, 
     NewEmployeeID = MAX(CASE WHEN o.level = 1 THEN o.val END) OVER(PARTITION BY t.OriginalFile), 
     NewEmployeeTitle = MAX(CASE WHEN o.level = 2 THEN o.val END) OVER(PARTITION BY t.OriginalFile), 
     NewLocation = MAX(CASE WHEN o.level = 3 THEN o.val END) OVER(PARTITION BY t.OriginalFile), 
     NewApplicationID = MAX(CASE WHEN o.level = 4 THEN o.val END) OVER(PARTITION BY t.OriginalFile) 
    FROM dbo.UploadAppTable t CROSS APPLY dbo.SplitStrings_CTE(t.OriginalFile, '-') o 
) 
    UPDATE cte 
    SET EmployeeID = NewEmployeeID, 
     EmployeeTitle = NewEmployeeTitle, 
     Location = NewLocation, 
     ApplicationID = NewApplicationID 

演示SQLFiddle

Answer 2

你想要做类似OriginalFile.Split('-')的东西，对不对？可悲的是，在SQL Server中没有可用的内部字符串分割，您将不得不推出自己的。随后，Erland Sommarskog为每个人都省下了不必担心的问题，因为有些优秀的文章可以找到，您可以找到here。