आपकी सलाह और एक स्क्रिप्ट जो मुझे ऑनलाइन मिली, को मिलाकर, मैंने एक ऐसी प्रक्रिया बनाई जो SQL का उत्पादन करेगी जिसे आप ON DELETE CASCADE की परवाह किए बिना एक कैस्केड डिलीट करने के लिए चला सकते हैं। . यह शायद समय की एक बड़ी बर्बादी थी, लेकिन मेरे पास इसे लिखने में अच्छा समय था। इसे इस तरह से करने का एक फायदा यह है कि आप एक GO डाल सकते हैं प्रत्येक पंक्ति के बीच कथन, और यह एक बड़ा लेन-देन नहीं होना चाहिए। मूल एक पुनरावर्ती प्रक्रिया थी; यह एक स्टैक टेबल में रिकर्सन को अनियंत्रित करता है।
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'
