在 SQL Server 2017 中使用 STRING_AGG 获取唯一值

Question

The following query:

SELECT T1.REPORTED_NAME, STRING_AGG(CAST(T1.ENTRY AS NVARCHAR(MAX)),',') AS Average_Str
FROM Table1 T1
INNER JOIN Table2 T2 ON T1.ID = T2.ProdID
WHERE T1.ENTRY like '%[A-Za-z]%'
GROUP BY T1.REPORTED_NAME
ORDER BY T1.REPORTED_NAME

Returns:

REPORTED_NAME       Average_Str
Report_1            Failed,Failed,Failed,Failed,Failed,
Report_2            Passed,Passed,Passed

I would like my final output to have only unique value as below

REPORTED_NAME       Average_Str
Report_1            Failed
Report_2            Passed

Thank you in advance for your help

Answer 1

You can go for first getting unique values and then applying string aggregate like below:

;WITH CTE_UniqueValues
(
SELECT Reported_Name, Entry, MAX(ID) AS ID
FROM Table1
GROUP BY Reported_Name, Entry
)
SELECT T1.REPORTED_NAME, STRING_AGG(CAST(T1.ENTRY AS NVARCHAR(MAX)),',') AS Average_Str
FROM CTE_UniqueValues T1
INNER JOIN Table2 T2 ON T1.ID = T2.ProdID
WHERE T1.ENTRY like '%[A-Za-z]%'
GROUP BY T1.REPORTED_NAME
ORDER BY T1.REPORTED_NAME