Wie verwendet man Unterabfragen in USQL?

Question

Ich erhalte Compilation Fehler während follwowing Abfrage in u-SQL verwenden:

@CourseDataExcludingUpdatedCourse = SELECT * FROM @CourseData AS cd 
WHERE cd.CourseID NOT IN (SELECT CourseID FROM @UpdatedCourseData); 

Es ist nicht erlaubt mir NOT IN Clause in Unterabfrage zu verwenden. Ich möchte alle Datensätze anzeigen, die nicht in @UpdatedCourseData vorhanden sind. Wie erreiche ich das in U-SQL?

Answer 1

In U-SQL NOT EXISTS als ANTISEMIJOIN implementiert ist, so etwas wie dieses:

@CourseDataExcludingUpdatedCourse = 
    SELECT cd.* 
    FROM @CourseData AS cd 
     ANTISEMIJOIN 
      @UpdatedCourseData AS us 
     ON cd.courseId == us.courseId; 

Sehen Sie hier für weitere Informationen:

https://msdn.microsoft.com/en-us/library/azure/mt621330.aspx

Answer 2

@employees = 
    SELECT * FROM 
     (VALUES 
     (1, "Noah", 100, (int?)10000, new DateTime(2012,05,31)), 
     (2, "Sophia", 100, (int?)15000, new DateTime(2012,03,19)), 
     (3, "Liam", 100, (int?)30000, new DateTime(2014,09,14)), 
     (4, "Amy", 100, (int?)35000, new DateTime(1999,02,27)), 
     (5, "Justin", 600, (int?)15000, new DateTime(2015,01,12)), 
     (6, "Emma", 200, (int?)8000, new DateTime(2014,03,08)), 
     (7, "Jacob", 200, (int?)8000, new DateTime(2014,09,02)), 
     (8, "Olivia", 200, (int?)8000, new DateTime(2013,12,11)), 
     (9, "Mason", 300, (int?)50000, new DateTime(2016,01,01)), 
     (10, "Ava", 400, (int?)15000, new DateTime(2014,09,14)) 
     ) AS T(EmpID, EmpName, DeptID, Salary, StartDate); 

@departments = 
    SELECT * FROM 
     (VALUES 
     (100, "Engineering"), 
     (200, "HR"), 
     (300, "Executive"), 
     (400, "Marketing"), 
     (500, "Sales"), 
     (600, "Clerical"), 
     (800, "Reserved") 
     ) AS T(DeptID, DeptName); 

/* T-SQL; Using a subquery with IN 
SELECT * 
FROM @employees 
WHERE DeptID IN 
    (SELECT DeptID FROM @departments WHERE DeptName IN ('Engineering', 'Executive')); 
*/ 

// U-SQL; Using SEMIJOIN 
@result = 
    SELECT * 
    FROM @employees AS e 
    LEFT SEMIJOIN (SELECT DeptID FROM @departments WHERE DeptName IN ("Engineering", "Executive")) AS sc 
    ON e.DeptID == sc.DeptID; 

OUTPUT @result 
TO "/Output/ReferenceGuide/Joins/SemiJoins/SubqueryIN.txt" 
USING Outputters.Tsv(outputHeader: true); 

/* T-SQL; Using a subquery with NOT IN 
SELECT * 
FROM @employees 
WHERE DeptID NOT IN 
    (SELECT DeptID FROM @departments WHERE DeptName IN ('Engineering', 'Executive')); 
*/ 

// U-SQL; Using ANTISEMIJOIN 
@result = 
    SELECT * 
    FROM @employees AS e 
    LEFT ANTISEMIJOIN (SELECT DeptID FROM @departments WHERE DeptName IN ("Engineering", "Executive")) AS sc 
    ON e.DeptID == sc.DeptID; 

OUTPUT @result 
TO "/Output/ReferenceGuide/Joins/AntiSemiJoins/SubqueryNOTIN.txt" 
USING Outputters.Tsv(outputHeader: true); 

// BONUS: Switch "LEFT" to "RIGHT" in the above examples and observe the results.