database - 如何在sql server中查找循环依赖表

Question

目前我正在寻找数据库中表的依赖顺序。而且我对数据库中某些表的循环依赖问题感到困惑。

因为有些表是循环依赖的，我没有得到整个订单.....

有没有办法在sql server的任何数据库中找到循环依赖表，除了数据库图？

score 12 · Accepted Answer

您真的不需要购买工具来查找这些参考资料。

SELECT 
  OBJECT_SCHEMA_NAME(fk1.parent_object_id)
   + '.' + OBJECT_NAME(fk1.parent_object_id), 
  OBJECT_SCHEMA_NAME(fk2.parent_object_id)
   + '.' + OBJECT_NAME(fk2.parent_object_id)
FROM sys.foreign_keys AS fk1
INNER JOIN sys.foreign_keys AS fk2
ON fk1.parent_object_id = fk2.referenced_object_id
AND fk2.parent_object_id = fk1.referenced_object_id;

score 10 · Accepted Answer

我偶然发现了我现在发现在几个地方复制的我的脚本。我认为它最初来自SQL Azure 团队博客，在 2010 年的一篇文章中关于：

在关系数据库的世界中，循环引用是与表相关的外键创建循环的模式结构。尝试同步两个强制执行外键的关系数据库时，循环引用会导致特殊类型的问题。由于这个问题，包含循环引用的数据库模式在同步和复制数据库时可以使用的工具中受到限制。本文将解释循环引用并演示用于确定您的数据库是否具有循环引用的 Transact-SQL 脚本。

它也在这里复制并归功于韦恩·贝瑞（Wayne Berry）。也许他在 Sql Azure 团队？

@Aaron_Bertrand 的回答非常简洁。为了完整起见，我认为值得添加此脚本，因为它会找到更长的依赖链。该链接很难找到，我将在这里重现代码，而不仅仅是希望让下一个人更容易的链接。

它并不简洁。

下面的 Transact-SQL 脚本使用递归游标来检测数据库架构中是否存在任何循环引用。它可以在您尝试与 SQL Azure 同步之前在您的 SQL Server 数据库上运行，或者您可以在您的 SQL Azure 数据库上运行它。您可以在 SQL Server Management Studio 的查询窗口中运行它；输出将显示为消息部分。

如果您有循环引用，则输出将如下所示：

dbo.City -> dbo.Author -> dbo.City dbo.Division -> dbo.Author -> dbo.City -> dbo.County -> dbo.Region -> dbo.Image -> dbo.Division dbo.State - > dbo.Image -> dbo.Area -> dbo.Author -> dbo.City -> dbo.County -> dbo.Region -> >dbo.State dbo.County -> dbo.Region -> dbo.Author -> dbo.City -> dbo.County dbo.Image -> dbo.Area -> dbo.Author -> dbo.City -> dbo.County -> dbo.Region -> dbo.Image dbo.Location -> dbo.Author - > dbo.City -> dbo.County -> dbo.Region -> dbo.Image -> dbo.Location dbo.LGroup -> dbo.LGroup dbo.Region -> dbo.Author -> dbo.City -> dbo.County -> dbo.Region dbo.Author -> dbo.City -> dbo.Author dbo.Area -> dbo.Author -> dbo.City -> dbo.County -> dbo.Region -> dbo.Image -> dbo.区域

每一行都是一个循环引用，带有创建循环的表的链接列表。下面是用于检测循环引用的 Transact-SQL 脚本...此代码适用于 SQL Azure 和 SQL Server。

SET NOCOUNT ON

-- WWB: Create a Temp Table Of All Relationship To Improve Overall Performance
CREATE TABLE #TableRelationships (FK_Schema nvarchar(max), FK_Table nvarchar(max),
    PK_Schema nvarchar(max), PK_Table nvarchar(max))

-- WWB: Create a List Of All Tables To Check
CREATE TABLE #TableList ([Schema] nvarchar(max), [Table] nvarchar(max))

-- WWB: Fill the Table List
INSERT INTO #TableList ([Table], [Schema])
SELECT TABLE_NAME, TABLE_SCHEMA
FROM INFORMATION_SCHEMA.TABLES 
WHERE Table_Type = 'BASE TABLE'

-- WWB: Fill the RelationShip Temp Table
INSERT INTO #TableRelationships(FK_Schema, FK_Table, PK_Schema, PK_Table)
SELECT
    FK.TABLE_SCHEMA,
    FK.TABLE_NAME,
    PK.TABLE_SCHEMA,
    PK.TABLE_NAME
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C
      INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK ON 
        C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME
      INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK ON 
        C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME
      INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE CU ON 
        C.CONSTRAINT_NAME = CU.CONSTRAINT_NAME
      INNER JOIN (
            SELECT i1.TABLE_NAME, i2.COLUMN_NAME
            FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS i1
            INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE i2 ON
             i1.CONSTRAINT_NAME = i2.CONSTRAINT_NAME
            WHERE i1.CONSTRAINT_TYPE = 'PRIMARY KEY'
) PT ON PT.TABLE_NAME = PK.TABLE_NAME

CREATE TABLE #Stack([Schema] nvarchar(max), [Table] nvarchar(max))

GO

-- WWB: Drop SqlAzureRecursiveFind
IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = 
    OBJECT_ID(N'[dbo].[SqlAzureRecursiveFind]') AND type in (N'P', N'PC'))
DROP PROCEDURE [dbo].[SqlAzureRecursiveFind]

GO

-- WWB: Create a Stored Procedure that Recursively Calls Itself
CREATE PROC SqlAzureRecursiveFind
    @BaseSchmea nvarchar(max),
    @BaseTable nvarchar(max),
    @Schmea nvarchar(max),
    @Table nvarchar(max),
    @Fail nvarchar(max) OUTPUT
AS

    SET NOCOUNT ON

    -- WWB: Keep Track Of the Schema and Tables We Have Checked
    -- Prevents Looping          
    INSERT INTO #Stack([Schema],[Table]) VALUES (@Schmea, @Table)

    DECLARE @RelatedSchema nvarchar(max)
    DECLARE @RelatedTable nvarchar(max)

    -- WWB: Select all tables that the input table is dependent on
    DECLARE table_cursor CURSOR LOCAL  FOR
          SELECT PK_Schema, PK_Table
          FROM #TableRelationships
          WHERE FK_Schema = @Schmea AND FK_Table = @Table

    OPEN table_cursor;

    -- Perform the first fetch.
    FETCH NEXT FROM table_cursor INTO @RelatedSchema, @RelatedTable;

    -- Check @@FETCH_STATUS to see if there are any more rows to fetch.
    WHILE @@FETCH_STATUS = 0
    BEGIN

        -- WWB: If We have Recurred To Where We Start This
        -- Is a Circular Reference
        -- Begin failing out of the recursions
        IF (@BaseSchmea = @RelatedSchema AND 
                @BaseTable = @RelatedTable)
            BEGIN
                SET @Fail = @RelatedSchema + '.' + @RelatedTable
                RETURN
            END
        ELSE            
        BEGIN

            DECLARE @Count int

            -- WWB: Check to make sure that the dependencies are not in the stack
            -- If they are we don't need to go down this branch
            SELECT    @Count = COUNT(1)
            FROM    #Stack    
            WHERE    #Stack.[Schema] = @RelatedSchema AND 
                #Stack.[Table] = @RelatedTable

            IF (@Count=0) 
            BEGIN
                -- WWB: Recurse
                EXECUTE SqlAzureRecursiveFind @BaseSchmea, 
                    @BaseTable, 
                    @RelatedSchema, @RelatedTable, @Fail OUTPUT
                IF (LEN(@Fail) > 0)
                BEGIN
                    -- WWB: If the Call Fails, Build the Output Up
                    SET @Fail = @RelatedSchema + '.' + @RelatedTable 
                        + ' -> ' + @Fail
                    RETURN
                END
            END
       END

       -- This is executed as long as the previous fetch succeeds.
    FETCH NEXT FROM table_cursor INTO @RelatedSchema, @RelatedTable;
    END

    CLOSE table_cursor;
    DEALLOCATE table_cursor;    

GO    

SET NOCOUNT ON

DECLARE @Schema nvarchar(max)
DECLARE @Table nvarchar(max)
DECLARE @Fail nvarchar(max)

-- WWB: Loop Through All the Tables In the Database Checking Each One
DECLARE list_cursor CURSOR FOR
      SELECT [Schema], [Table]
      FROM #TableList

OPEN list_cursor;

-- Perform the first fetch.
FETCH NEXT FROM list_cursor INTO @Schema, @Table;

-- Check @@FETCH_STATUS to see if there are any more rows to fetch.
WHILE @@FETCH_STATUS = 0
BEGIN

    -- WWB: Clear the Stack (Don't you love Global Variables)
    DELETE #Stack

    -- WWB: Initialize the Input
    SET @Fail = ''

    -- WWB: Check the Table
    EXECUTE SqlAzureRecursiveFind @Schema, 
        @Table, @Schema,
         @Table, @Fail OUTPUT
    IF (LEN(@Fail) > 0)
    BEGIN
        -- WWB: Failed, Output
        SET @Fail = @Schema + '.' + @Table + ' -> ' + @Fail
        PRINT @Fail
    END

   -- This is executed as long as the previous fetch succeeds.
    FETCH NEXT FROM list_cursor INTO @Schema, @Table;
END

-- WWB: Clean Up
CLOSE list_cursor;
DEALLOCATE list_cursor;    

DROP TABLE #TableRelationships
DROP TABLE #Stack
DROP TABLE #TableList
DROP PROC SqlAzureRecursiveFind

score 0 · Accepted Answer

下载 Sql Dependency Tracker 的免费试用版并试一试。如果它适合您，请购买 :-)

http://www.red-gate.com/products/sql-development/sql-dependency-tracker/

另一个选择是 ApexSQL：

http://knowledgebase.apexsql.com/2012/08/apexsql-search-dependency-viewer.html

两者都是很好的工具。

score 0 · Accepted Answer

答案1中来自 SQL Azure 团队博客的脚本，它仅显示自引用 - 与同一个表的父/子关系。所以我写了自己的脚本：

-- variables for the path output
declare @delimList nvarchar(max) = ' > ',
        @delimDot nvarchar(max) = '.'

/* Part 1: read all fk-pk relation
does not perform well in SQL Server with a CTE, thus using a temp table */
create table #fk_pk(
    PK_schema sysname not null,
    PK_table sysname not null,
    FK_schema sysname not null,
    FK_table sysname not null
)

insert into #fk_pk(
    PK_schema,
    PK_table,
    FK_schema,
    FK_table
)
select      distinct
            PK.TABLE_SCHEMA PK_schema,
            PK.TABLE_NAME PK_table,
            FK.TABLE_SCHEMA FK_schema,
            FK.TABLE_NAME FK_table
from        INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK
            inner join
            INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C
            on C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME
            inner join
            INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK
            on C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME
where       PK.CONSTRAINT_TYPE = 'PRIMARY KEY'
            and
            -- ignore self-references
            not (
                PK.TABLE_SCHEMA = FK.TABLE_SCHEMA
                and
                PK.TABLE_NAME = FK.TABLE_NAME
            )

;
with relation(
    sourceSchema,
    sourceTable,
    PK_schema,
    PK_table,
    FK_schema,
    FK_table,
    path
) as (
    /* Part 2: Find PKs that are referenced more then once (reduces workload for next step) */
    -- anchor: more then one fk reference these pk tables
    select      fk_pk.PK_schema sourceSchema,
                fk_pk.PK_table sourceTable,
                fk_pk.PK_schema,
                fk_pk.PK_table,
                fk_pk.FK_schema,
                fk_pk.FK_table,
                cast(fk_pk.PK_schema as nvarchar(max)) + @delimDot + fk_pk.PK_table + @delimList + fk_pk.FK_schema + @delimDot +  fk_pk.FK_table path
    from        #fk_pk fk_pk
    where       exists(
                    select      1
                    from        #fk_pk fk_pk_exists
                    where       fk_pk_exists.PK_schema = fk_pk.PK_schema
                                and
                                fk_pk_exists.PK_table = fk_pk.PK_table
                                and
                                not (
                                    fk_pk_exists.FK_schema = fk_pk.FK_schema
                                    and
                                    fk_pk_exists.FK_table = fk_pk.FK_table
                                )
                )

    /* Part 3: Find all possible paths from those PK tables to any other table (using recursive CTE) */
    union all

    -- recursive
    select      relation.sourceSchema,
                relation.sourceTable,
                fk_pk_child.PK_schema,
                fk_pk_child.PK_table,
                fk_pk_child.FK_schema,
                fk_pk_child.FK_table,
                /* Part 5: Display result nicely
                compose a path like: A -> B -> C */
                relation.path + @delimList + fk_pk_child.FK_schema + @delimDot + fk_pk_child.FK_table path
    from        #fk_pk fk_pk_child
                inner join
                relation
                on  relation.FK_schema = fk_pk_child.PK_schema
                    and
                    relation.FK_table = fk_pk_child.PK_table
)

/* Part 4: Identify problematic circles */
select      relation.sourceSchema + @delimDot + relation.sourceTable source,
            relation.FK_schema + @delimDot + relation.FK_table target,
            relation.path
from        relation
where       exists(
                select      1
                from        relation relation_exists
                where       relation_exists.sourceSchema = relation.sourceSchema
                            and
                            relation_exists.sourceTable = relation.sourceTable
                            and
                            not (
                                relation_exists.PK_schema = relation.PK_schema
                                and
                                relation_exists.PK_table = relation.PK_table
                            )
                            and
                            relation_exists.FK_schema = relation.FK_schema
                            and
                            relation_exists.FK_table = relation.FK_table

            )
order by    relation.sourceSchema,
            relation.sourceTable,
            relation.FK_schema,
            relation.FK_table,
            relation.path

drop table #fk_pk
go

它报告循环引用和形成循环的路径。

该脚本仅适用于 SQL Server，托管在github 存储库中，并附有代码说明。如果您将其移植到其他 RDBMS，请告诉我。

database - 如何在sql server中查找循环依赖表

4 回答 4

Related

Reference