sql-server - 在 SQL Server 2005 中，我可以在不设置表属性的情况下执行级联删除吗？

Question

我有一个充满客户数据的数据库。它太大了，操作起来确实很麻烦，我宁愿把它缩小到 10% 的客户，这对于开发来说已经足够了。我有很多表，我不想用“ON DELETE CASCADE”来更改它们，特别是因为这是一次性交易。

我可以在不先设置表的情况下执行级联所有表的删除操作吗？如果没有，我最好的选择是什么？

Answer 1

结合您的建议和我在网上找到的脚本，我制作了一个过程，该过程将生成 SQL，您可以运行该 SQL 来执行级联删除，而不管ON DELETE CASCADE如何。这可能是浪费时间，但我写得很开心。这样做的一个优点是，您可以在每一行之间放置一个 GO 语句，并且它不必是一个大事务。最初是一个递归过程；这个将递归展开到堆栈表中。

create procedure usp_delete_cascade (
    @base_table_name varchar(200), @base_criteria nvarchar(1000)
)
as begin
    -- Adapted from http://www.sqlteam.com/article/performing-a-cascade-delete-in-sql-server-7
    -- Expects the name of a table, and a conditional for selecting rows
    -- within that table that you want deleted.
    -- Produces SQL that, when run, deletes all table rows referencing the ones
    -- you initially selected, cascading into any number of tables,
    -- without the need for "ON DELETE CASCADE".
    -- Does not appear to work with self-referencing tables, but it will
    -- delete everything beneath them.
    -- To make it easy on the server, put a "GO" statement between each line.

    declare @to_delete table (
        id int identity(1, 1) primary key not null,
        criteria nvarchar(1000) not null,
        table_name varchar(200) not null,
        processed bit not null,
        delete_sql varchar(1000)
    )

    insert into @to_delete (criteria, table_name, processed) values (@base_criteria, @base_table_name, 0)

    declare @id int, @criteria nvarchar(1000), @table_name varchar(200)
    while exists(select 1 from @to_delete where processed = 0) begin
        select top 1 @id = id, @criteria = criteria, @table_name = table_name from @to_delete where processed = 0 order by id desc

        insert into @to_delete (criteria, table_name, processed)
            select referencing_column.name + ' in (select [' + referenced_column.name + '] from [' + @table_name +'] where ' + @criteria + ')',
                referencing_table.name,
                0
            from  sys.foreign_key_columns fk
                inner join sys.columns referencing_column on fk.parent_object_id = referencing_column.object_id 
                    and fk.parent_column_id = referencing_column.column_id 
                inner join  sys.columns referenced_column on fk.referenced_object_id = referenced_column.object_id 
                    and fk.referenced_column_id = referenced_column.column_id 
                inner join  sys.objects referencing_table on fk.parent_object_id = referencing_table.object_id 
                inner join  sys.objects referenced_table on fk.referenced_object_id = referenced_table.object_id 
                inner join  sys.objects constraint_object on fk.constraint_object_id = constraint_object.object_id
            where referenced_table.name = @table_name
                and referencing_table.name != referenced_table.name

        update @to_delete set
            processed = 1
        where id = @id
    end

    select 'print ''deleting from ' + table_name + '...''; delete from [' + table_name + '] where ' + criteria from @to_delete order by id desc
end

exec usp_delete_cascade 'root_table_name', 'id = 123'