Question

我有这样的文件夹结构：

Folder1
  Folder1.1
  Folder1.2
Folder2
  Folder2.1
    Folder2.1.1
and so on..

问题是如何级联删除它们（即删除folder2时所有子项也被删除）。我无法设置ON DELETE操作，因为MSSQL不允许它。你能提出一些建议吗？

更新：我写了这个存储过程，我可以留下它还是需要进行一些修改？

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

CREATE PROCEDURE sp_DeleteFoldersRecursive
    @parent_folder_id int
AS
BEGIN
    SET NOCOUNT ON;

    IF @parent_folder_id = 0 RETURN;

    CREATE TABLE #temp(fid INT );

    DECLARE @Count INT;

    INSERT INTO #temp(fid)
    SELECT FolderId FROM Folders WHERE FolderId = @parent_folder_id;

    SET @Count = @@ROWCOUNT;

    WHILE @Count > 0
    BEGIN
        INSERT INTO #temp(fid) 
            SELECT FolderId FROM Folders WHERE EXISTS
                   (SELECT FolderId  FROM #temp
                    WHERE Folders.ParentId = #temp.fid)
             AND  NOT EXISTS
                  (SELECT FolderId FROM #temp
                   WHERE Folders.FolderId = #temp.fid);    

             SET @Count = @@ROWCOUNT;         
    END

    DELETE Folders FROM Folders INNER JOIN #temp ON Folders.FolderId = #temp.fid; 
    DROP TABLE #temp;
END
GO

Answer 1

通常它是存储过程或INSTEAD OF触发器。

那是：

从参数/ DELETED（例如递归CTE方法）生成Folder2的层次结构））
在一个DELETE语句中删除此层次结构

循环级联/外键违规不会触发。

实体框架自引用实体删除

1 个答案: