錯誤：ORDER BY項目必須出現在選擇列表中，如果SELECT DISTINCT指定

Question

我收到錯誤：

ORDER BY items must appear in the select list if SELECT DISTINCT is specified.

對於此查詢：

SELECT DISTINCT 
    [Theme].[Name], [ThemeType].[Type] 
FROM 
    [Theme] 
LEFT OUTER JOIN 
    [ThemeType] ON [Theme].[ThemeTypeId] = [ThemeType].[PK_ThemeType] 
JOIN 
    [ProductTheme] ON [ProductTheme].[ThemeId]=[Theme].[PK_Theme] 
WHERE 
    ProductTheme.ProductID LIKE '%' 
    AND ProductTheme.ThemeId = Theme.PK_Theme 
    AND COALESCE([THEME].[THEMETYPEID], 'null') LIKE '%[0-9]%' 
ORDER BY 
    CASE WHEN [THEMETYPE].[TYPE] IS NULL 
      THEN 0 
      ELSE 1 
    END, [THEMETYPE].[TYPE] 

我已經考慮它，而不是定義案例似乎是一個常見問題，但我確實如此。我究竟做錯了什麼？

Answer 1

而不是使用SELECT DISTINCT，使用GROUP BY（以匹配註釋指定的排序順序）：

SELECT 
    [Theme].[Name], [ThemeType].[Type] 
FROM 
    [Theme] 
LEFT OUTER JOIN 
    [ThemeType] ON [Theme].[ThemeTypeId] = [ThemeType].[PK_ThemeType] 
JOIN 
    [ProductTheme] ON [ProductTheme].[ThemeId]=[Theme].[PK_Theme] 
WHERE 
    ProductTheme.ProductID LIKE '%' 
    AND ProductTheme.ThemeId = Theme.PK_Theme 
    AND COALESCE([THEME].[THEMETYPEID], 'null') LIKE '%[0-9]%' 
GROUP BY 
    [Theme].[Name], [ThemeType].[Type] 
ORDER BY 
    CASE WHEN [ThemeType].[Type] IS NULL 
      THEN 0 
      ELSE 1 
    END, [Theme].[Name]