如何将 List_File_Path 传递给 Azure 数据工厂 U-SQL activity?

How do you pass a List_File_Path to an Azure Data Factory U-SQL activity?

Input Files (U-SQL) 声明输入路径可以采用以下任何形式:

Input_File_Path :=                                                                                       
     Single_File_Path 
|    List_File_Path 
|    File_Set_Path.

作为 List_File_Path 的示例,他们提供:

@searchLog =  
    EXTRACT UserId          int  
          , Start           DateTime  
          , Region          string  
          , Query           string  
          , Duration        int  
          , Urls            string  
          , ClickedUrls     string
    FROM "/Samples/Outputs/ExampleA.csv",
         "/Samples/Outputs/ExampleB.csv"
    USING Extractors.Csv();

我有以下代码:

DECLARE EXTERNAL @FileList string = "ListOfFiles.txt";
@searchLog =  
    EXTRACT UserId          int  
          , Start           DateTime  
          , Region          string  
          , Query           string  
          , Duration        int  
          , Urls            string  
          , ClickedUrls     string
    FROM @FileList
    USING Extractors.Csv();

如果我将参数 FileList 作为 @variables('FileList') 传递,其中 FileList 是一个数组,我得到以下错误:

Error Id: E_STORE_USER_FAILURE_83090017, Error Message: Invalid pathname Cosmos Path:

它将 FileList 视为:"System.Collections.Generic.List1[System.Object]"`

如果我将参数 FileList 传递为 @join(variables('FileList'),',') 如果将 FileList 视为:"Dir/File1.txt,Dir/File2.txt" 也就是说,就好像它是单个文件名一样。

我也试过用 @join(variables('FileList'),',') 来做这个:

DECLARE EXTERNAL @FileList string = "ListOfFiles.txt";
@searchLog =  
    EXTRACT UserId          int  
          , Start           DateTime  
          , Region          string  
          , Query           string  
          , Duration        int  
          , Urls            string  
          , ClickedUrls     string
    FROM @FileList.Split(',')
    USING Extractors.Csv();

但这会产生以下错误:C# error CS0029: Cannot implicitly convert type 'string[]' to 'string'

有办法解决这个问题吗?

请试试这个:

U-SQL:

DECLARE EXTERNAL @FileList1 string = "ListOfFiles.txt";
DECLARE EXTERNAL @FileList2 string = "ListOfFiles.txt";

@searchLog =  
    EXTRACT UserId          int  
          , Start           DateTime  
          , Region          string  
          , Query           string  
          , Duration        int  
          , Urls            string  
          , ClickedUrls     string
    FROM @FileList1,@FileList2
    USING Extractors.Csv();

OUTPUT @searchLog
TO "/output/exampleD.csv" 
USING Outputters.Csv();

参数: