Question

我试图删除数据库中的所有表，而不必按正确的顺序执行。从我所看到的运行NOCHECK命令将阻止检查外键。但是，即使在运行之后我仍然会在尝试删除第一个表时出错。

无法删除对象＆＃39; dbo.TABLENAME＆＃39;因为它被引用 FOREIGN KEY约束

我之前已经看到这个问题得到了成功解答，所以我不明白与我在做什么有什么不同。这是在SQL Server 2008 R2上运行。

BEGIN TRANSACTION

--get current list of tables
SELECT QUOTENAME(s.NAME) + '.' + QUOTENAME(t.NAME) as 'Dropped Table'
FROM   sys.tables t
       JOIN sys.schemas s
         ON t.[schema_id] = s.[schema_id]
WHERE  t.type = 'U'


--disable constraint checking in all tables
DECLARE @sql NVARCHAR(max)
SET @sql = ''
SELECT @sql += ' ALTER TABLE ' + QUOTENAME(s.NAME) + '.' + QUOTENAME(t.NAME) + ' NOCHECK CONSTRAINT ALL; '
FROM   sys.tables t
       JOIN sys.schemas s
         ON t.[schema_id] = s.[schema_id]
WHERE  t.type = 'U'
select @sql
Exec sp_executesql @sql

--disable all constraints (this also didn't work)
--EXEC sp_MSforeachtable "ALTER TABLE ? NOCHECK CONSTRAINT all"


--drop all tables
SET @sql = ''
SELECT @sql += ' DROP TABLE ' + QUOTENAME(s.NAME) + '.' + QUOTENAME(t.NAME) + '; '
FROM   sys.tables t
       JOIN sys.schemas s
         ON t.[schema_id] = s.[schema_id]
WHERE  t.type = 'U'
select @sql
Exec sp_executesql @sql


--check current list, should be empty
SELECT QUOTENAME(s.NAME) + '.' + QUOTENAME(t.NAME) as 'Tables'
FROM   sys.tables t
       JOIN sys.schemas s
         ON t.[schema_id] = s.[schema_id]
WHERE  t.type = 'U'

ROLLBACK TRANSACTION

更新1

我删除了约束禁用代码来代替约束丢弃代码，但是它给出了错误。

--drop all constraints
DECLARE @sql NVARCHAR(max)
SET @sql = ''
SELECT @sql += ' ALTER TABLE ' +QUOTENAME(s.NAME) + '.' + QUOTENAME(t.NAME) + ' DROP CONSTRAINT ' + ctu.CONSTRAINT_NAME + ';'
FROM sys.tables t
    JOIN sys.schemas s
        ON t.[schema_id] = s.[schema_id]
    INNER JOIN EOS_DEV.INFORMATION_SCHEMA.CONSTRAINT_TABLE_USAGE as ctu
        ON ctu.TABLE_SCHEMA = s.name AND ctu.TABLE_NAME = t.name
WHERE  t.type = 'U'
Exec sp_executesql @sql

约束＆＃39; [CONSTRAINT_NAME]＆＃39;正在被表引用＆＃39; [TABLE_NAME]＆＃39;，外键约束＆＃39; [FK_NAME]＆＃39;

如何修改此查询，以便仅针对FK约束？

Answer 1

将FK设置为NOCHECK将允许您INSERT，UPDATE或DELETE违反约束的行。它不允许您DROP或TRUNCATE目标表。 EG：

use tempdb

create table a(id int primary key)

create table b(id int primary key, aid int references a)

alter table b nocheck constraint all

insert into b(id,aid) values (1,1) --succeeds because of nocheck

drop table a --fails
--Msg 3726, Level 16, State 1, Line 11
--Could not drop object 'a' because it is referenced by a FOREIGN KEY constraint.

Answer 2

你必须这么难吗？为什么不只是还原一个空数据库（或只包含您的架构的数据库以及需要什么“默认”行）？

Answer 3

感谢大家的帮助。我更新了我的查询，现在可以确认它能够不加选择地删除所有表。我还添加了一个部分来删除所有存储过程以获得一些额外的味道。

BEGIN TRANSACTION

--get current list of tables
SELECT QUOTENAME(s.NAME) + '.' + QUOTENAME(t.NAME) as 'Dropped Table'
FROM   sys.tables t
       JOIN sys.schemas s
         ON t.[schema_id] = s.[schema_id]
WHERE  t.type = 'U'

--drop all constraints
DECLARE @sql NVARCHAR(max)
SET @sql = ''
SELECT @sql += ' ALTER TABLE ' +QUOTENAME(s.NAME) + '.' + QUOTENAME(t.NAME) + ' DROP CONSTRAINT ' + tc.CONSTRAINT_NAME + ';'
FROM sys.tables t
    JOIN sys.schemas s
        ON t.[schema_id] = s.[schema_id]
    INNER JOIN EOS_DEV.INFORMATION_SCHEMA.TABLE_CONSTRAINTS as tc
        ON tc.TABLE_SCHEMA = s.name AND tc.TABLE_NAME = t.name
WHERE t.type = 'U'
    AND tc.CONSTRAINT_TYPE = 'FOREIGN KEY'
Exec sp_executesql @sql

--drop all tables
SET @sql = ''
SELECT @sql += ' DROP TABLE ' + QUOTENAME(s.NAME) + '.' + QUOTENAME(t.NAME) + '; '
FROM   sys.tables t
       JOIN sys.schemas s
         ON t.[schema_id] = s.[schema_id]
WHERE  t.type = 'U'
Exec sp_executesql @sql

--drop all stored procs
SET @sql = ''
SELECT @sql += 'DROP PROCEDURE [' + SCHEMA_NAME(p.schema_id) + '].[' + p.NAME + ']'
FROM sys.procedures as p 
where p.is_ms_shipped = 0
    AND p.type = 'P'
Exec sp_executesql @sql

ROLLBACK TRANSACTION

T-SQL删除所有表

3 个答案: