Question

此代码涉及一个递归的存储过程调用和一个避免游标名称冲突的“不那么好”的方法。最后我不在乎它是否使用游标。只是寻找最优雅的方法。我主要将它用作跟踪存储过程层次结构（不购买产品）的简单方法。我在“动态sql”中尝试了游标并且没有太多运气。我想深入10级。

所需的输出：

sp_Master_Proc_Name  
-- sp_Child_Proc_1_Name  
---- sp_Sub_Proc_1_Name    
-- sp_Child_Proc_2_Name  
-- sp_Child_Proc_3_Name

它不漂亮，但这是代码（它没有按预期工作）

    CREATE PROCEDURE SP_GET_DEPENDENCIES
    (
      @obj_name varchar(300),
      @level int
    )
    AS
    DECLARE @sub_obj_name varchar(300)
    IF @level = 1
      BEGIN
        PRINT @obj_name
      END

    IF @level = 1
      BEGIN 
        DECLARE the_cursor_1 CURSOR FOR 
            SELECT DISTINCT REPLICATE('--', @level) + ' ' + c.name FROM dbo.sysdepends a
              INNER JOIN dbo.sysobjects b ON a.id = b.id
              INNER JOIN dbo.sysobjects c ON a.depid = c.id
              WHERE b.name = @obj_name
        OPEN the_cursor_1
        SET @level = @level + 1
        FETCH NEXT FROM the_cursor_1 INTO @sub_obj_name 
        WHILE @@FETCH_STATUS = 0 
          BEGIN 
            PRINT @sub_obj_name
            EXEC SP_GET_DEPENDENCIES @sub_obj_name, @level 
            FETCH NEXT FROM the_cursor_1 INTO @sub_obj_name 
          END
        CLOSE the_cursor_1
        DEALLOCATE the_cursor_1
      END

    IF @level = 2
      BEGIN 
        DECLARE the_cursor_2 CURSOR FOR 
            SELECT DISTINCT REPLICATE('--', @level) + ' ' + c.name FROM dbo.sysdepends a
              INNER JOIN dbo.sysobjects b ON a.id = b.id
              INNER JOIN dbo.sysobjects c ON a.depid = c.id
              WHERE b.name = @obj_name
        OPEN the_cursor_2
        SET @level = @level + 1
        FETCH NEXT FROM the_cursor_2 INTO @sub_obj_name 
        WHILE @@FETCH_STATUS = 0 
          BEGIN 
            PRINT @sub_obj_name
            EXEC SP_GET_DEPENDENCIES @sub_obj_name, @level 
            FETCH NEXT FROM the_cursor_2 INTO @sub_obj_name 
          END
        CLOSE the_cursor_2
        DEALLOCATE the_cursor_2
      END

    IF @level = 3
      BEGIN 
        DECLARE the_cursor_3 CURSOR FOR 
            SELECT DISTINCT REPLICATE('--', @level) + ' ' + c.name FROM dbo.sysdepends a
              INNER JOIN dbo.sysobjects b ON a.id = b.id
              INNER JOIN dbo.sysobjects c ON a.depid = c.id
              WHERE b.name = @obj_name
        OPEN the_cursor_3
        SET @level = @level + 1
        FETCH NEXT FROM the_cursor_3 INTO @sub_obj_name 
        WHILE @@FETCH_STATUS = 0 
          BEGIN 
            PRINT @sub_obj_name
            EXEC SP_GET_DEPENDENCIES @sub_obj_name, @level 
            FETCH NEXT FROM the_cursor_3 INTO @sub_obj_name 
          END
        CLOSE the_cursor_3
        DEALLOCATE the_cursor_3
      END

Answer 1

对于ms sql server你可以使用CURSOR LOCAL，那么游标是sproc调用的本地，你的代码变得更加简单：

CREATE PROCEDURE uspPrintDependencies
(
    @obj_name varchar(300),
    @level int
)
AS
SET NOCOUNT ON
DECLARE @sub_obj_name varchar(300)

if @level > 0 begin
    PRINT Replicate(' ',@level) + @obj_name
end
else begin
    PRINT @obj_name
end

DECLARE myCursor CURSOR LOCAL FOR 
    SELECT 
        DISTINCT c.name 
    FROM dbo.sysdepends a
        INNER JOIN dbo.sysobjects b ON a.id = b.id
        INNER JOIN dbo.sysobjects c ON a.depid = c.id
    WHERE b.name = @obj_name
OPEN myCursor
SET @level = @level + 1
FETCH NEXT FROM myCursor INTO @sub_obj_name 
WHILE @@FETCH_STATUS = 0 BEGIN 
    EXEC uspPrintDependencies @sub_obj_name, @level 
    FETCH NEXT FROM myCursor INTO @sub_obj_name 
END
CLOSE myCursor
DEALLOCATE myCursor
GO

Answer 2

有关按深度排序查询表外键依赖关系的讨论，请参阅this Stackoverflow question - 这与您正在讨论的问题类似。答案中至少有两个解决这个问题的工作方案，而你所做的唯一真正的不同就是他们正在抓取的表格。 This posting有一个DB逆向工程脚本，它显示了如何使用许多主数据字典表。

T-SQL Puzzler - 爬行对象依赖项

2 个答案: