在开发过程中，很多时候要把结果集存放到临时表中，常用的方法有两种。
一. SELECT INTO
1. 使用select into会自动生成临时表，不需要事先创建
select * into #temp from sysobjects
select * from #temp
2. 如果当前会话中，已存在同名的临时表
select * into #temp from sysobjects
再次运行，则会报错提示：数据库中已存在名为 '%1!' 的对象。
Msg 2714, Level 16, State 6, Line 2
There is already an object named '#temp' in the database.
在使用select into前，可以先做一下判断：
if OBJECT_ID('tempdb..#temp') is not null
drop table #temp
select * into #temp from sysobjects
select * from #temp
3. 利用select into生成一个空表
如果要生成一个空的表结构，不包含任何数据，可以给定一个恒不等式如下：
select * into #temp from sysobjects where 1=2
select * from #temp
备注：(更新：2018-09-20)
(1) 通过select into复制表默认会保留identity列属性， 从linked server复制表则不会；
--server1, database1
create table test_identity(id int identity, value int)
insert into test_identity values(100) --server2, database2
select * into temp
from sever1.database1.dbo.test_identity select object_name(object_id) as table_name, name, is_identity,*
from sys.columns
where object_id=object_id('temp')
/*
table_name name is_identity
temp id 0
*/
(2) 列的是否为null属性默认直接复制，如果显式给定列值，则目标表的列属性不允许为null；
--principal_id列定义可为空
exec sp_help 'sys.objects' drop table if exists test_null01;
drop table if exists test_null02; select principal_id into test_null01 from sys.objects
select isnull(principal_id,0) as principal_id into test_null02 from sys.objects select name, is_nullable,* from sys.columns where object_id = object_id('test_null01')
--name is_nullable
--principal_id 1
select name, is_nullable,* from sys.columns where object_id = object_id('test_null02')
--name is_nullable
--principal_id 0 select isnull(null,'') c1 into test_null_01
select '' c1 into test_null_02
select 1 c1 into test_null_03 exec sp_columns test_null_01
exec sp_columns test_null_02
exec sp_columns test_null_03
--NULLABLE
--
(3) 如果显式给定列值为null，或者join后列值全部为null， 目标表中该列的数据类型默认为int，除非用CAST/CONVERT显式指定null列的数据类型；
--if get only null value after join, select into will use int for null-value columns as well
select null as data_type into test_data_type;
exec sp_columns test_data_type
(4) SELECT… INTO… 除了复制identity属性外，仅复制数据，所以原表上的约束/索引/压缩选项等都不会被复制，所以从columnstore的表拉数据出来，会发现表变大了很多了，因为columnstore默认压缩数据，这种场景可考虑使用insert into… with(tablock) select… 结合610跟踪标记来替代SELECT… INTO；
(5) 从SQL SERVER 2014起，SELECT …INTO…的插入操作，执行计划显示为并行化操作符，也即插入操作不再是单线程；
二. INSERT INTO
1. 使用insert into，需要先手动创建临时表
1.1 保存从select语句中返回的结果集
create table test_getdate(c1 datetime)
insert into test_getdate select GETDATE()
select * from test_getdate
1.2 保存从存储过程返回的结果集
create table #helpuser
(
UserName nvarchar(128),
RoleName nvarchar(128),
LoginName nvarchar(128),
DefDBName nvarchar(128),
DefSchemaName nvarchar(128),
UserID smallint,
SID smallint
) insert into #helpuser exec sp_helpuser select * from #helpuser
1.3 保存从动态语句返回的结果集
create table test_dbcc
(
TraceFlag varchar(100),
Status tinyint,
Global tinyint,
Session tinyint
) insert into test_dbcc exec('DBCC TRACESTATUS') select * from test_dbcc
对于动态SQL，或者类似DBCC这种非常规的SQL语句，都可以通过这种方式来保存结果集。
2. 不能嵌套使用insert exec语句
2.1 下面这个例子，尝试保存sp_help_job的结果集到临时表，发生错误
create table #JobInfo
(
job_id uniqueidentifier,
originating_server nvarchar(128),
name nvarchar(128),
enabled tinyint,
description nvarchar(512),
start_step_id int,
category nvarchar(128),
owner nvarchar(128),
notify_level_eventlog int,
notify_level_email int,
notify_level_netsend int,
notify_level_page int ,
notify_email_operator nvarchar(128),
notify_netsend_operator nvarchar(128),
notify_page_operator nvarchar(128),
delete_level int,
date_created datetime,
date_modified datetime,
version_number int,
last_run_date int,
last_run_time int,
last_run_outcome int,
next_run_date int,
next_run_time int,
next_run_schedule_id int,
current_execution_status int,
current_execution_step nvarchar(128),
current_retry_attempt int,
has_step int,
has_schedule int,
has_target int,
type int
) insert into #JobInfo exec msdb..sp_help_job
返回错误信息：INSERT EXEC 语句不能嵌套。
Msg 8164, Level 16, State 1, Procedure sp_get_composite_job_info, Line 72
An INSERT EXEC statement cannot be nested.
展开错误信息中的存储过程：
exec sp_helptext sp_get_composite_job_info
发现里面还有个INSERT INTO…EXEC的嵌套调用，SQL Server在语法上不支持。
INSERT INTO @xp_results
EXECUTE master.dbo.xp_sqlagent_enum_jobs @can_see_all_running_jobs, @job_owner, @job_id
2.2 可以用分布式查询来避免这个问题，这种写法在INSIDE SQL Server 2005中作者提到过
(1) 首先到打开服务器选项Ad Hoc Distributed Queries
exec sp_configure 'show advanced options',1
RECONFIGURE
GO
exec sp_configure 'Ad Hoc Distributed Queries',1
RECONFIGURE
GO
(2) 通过OPENROWSET连接到本机，运行存储过程，取得结果集
使用windows认证
select * into #JobInfo_S1
from openrowset('sqloledb', 'server=(local);trusted_connection=yes','exec msdb.dbo.sp_help_job') select * from #JobInfo_S1
使用SQL Server认证
SELECT * INTO #JobInfo_S2
FROM OPENROWSET('SQLOLEDB','127.0.0.1';'sa';'sa_password','exec msdb.dbo.sp_help_job') SELECT * FROM #JobInfo_S2
这样的写法，既免去了手动建表的麻烦，也可以避免insert exec 无法嵌套的问题。几乎所有SQL语句都可以使用。
--dbcc不能直接运行
SELECT a.* into #t
FROM OPENROWSET('SQLOLEDB','127.0.0.1';'sa';'sa_password',
'dbcc log(''master'',3)') AS a --可以变通一下
SELECT a.* into #t
FROM OPENROWSET('SQLOLEDB','127.0.0.1';'sa';'sa_password',
'exec(''DBCC LOG(''''master'''',3)'')') AS a
后续的SQL SERVER版本中，这种写法有限制 (更新：2018-09-19)
1. 在SQL SERVER 2008 R2下测试，问题如下：
--sp_help_job没问题
SELECT * FROM
OPENROWSET ('SQLOLEDB','Server=.\SQLEXPRESS;Trusted_Connection=yes','EXEC msdb.dbo.sp_help_job') --随手写了几个sp_who2, xp_fixeddrives, sp_helpdb，都失败了
select * from
OPENROWSET('SQLOLEDB','Server=.\SQLEXPRESS;TRUSTED_CONNECTION=YES;','exec sp_who2')
/*
Msg 7357, Level 16, State 2, Line 2
Cannot process the object "exec sp_who2". The OLE DB provider "SQLNCLI10" for linked server "(null)" indicates that either the object has no columns or the current user does not have permissions on that object.
*/ select * from
OPENROWSET('SQLOLEDB','Server=.\SQLEXPRESS;TRUSTED_CONNECTION=YES;','exec xp_fixeddrives')
/*
Msg 7357, Level 16, State 2, Line 1
Cannot process the object "exec xp_fixeddrives". The OLE DB provider "SQLNCLI10" for linked server "(null)" indicates that either the object has no columns or the current user does not have permissions on that object.
*/ select * from
OPENROWSET('SQLOLEDB','Server=.\SQLEXPRESS;TRUSTED_CONNECTION=YES;','exec sp_helpdb')
/*
Msg 208, Level 16, State 1, Procedure sp_helpdb, Line 51
Invalid object name '#spdbdesc'.
*/
2．在SQL SERVER 2012, 2014, 2016下测试，问题如下：
--sp_help_job也失败了
SELECT * FROM
OPENROWSET ('SQLOLEDB','Server=.\MSSQL2016;Trusted_Connection=yes','EXEC msdb.dbo.sp_help_job')
/*
Msg 11520, Level 16, State 1, Procedure sp_describe_first_result_set, Line 1
The metadata could not be determined because statement 'EXECUTE master.dbo.xp_sqlagent_is_starting @retval OUTPUT' in procedure 'sp_is_sqlagent_starting' invokes an extended stored procedure.*/ --sp_who2, xp_fixeddrives, sp_helpdb，错误也都相对统一了
select * from
OPENROWSET('SQLOLEDB','Server=.\MSSQL2016;TRUSTED_CONNECTION=YES;','exec sp_who2')
/*
Msg 11526, Level 16, State 1, Procedure sp_describe_first_result_set, Line 1
The metadata could not be determined because statement 'delete #tb1_sysprocesses
where lower(status) = 'sleeping'
and upper(cmd) in (' in procedure 'sp_who2' uses a temp table.
*/ select * from
OPENROWSET('SQLOLEDB','Server=.\MSSQL2016;TRUSTED_CONNECTION=YES;','exec xp_fixeddrives')
/*
Msg 11519, Level 16, State 1, Procedure sp_describe_first_result_set, Line 1
The metadata could not be determined because statement 'exec xp_fixeddrives' invokes an extended stored procedure.
*/ select * from
OPENROWSET('SQLOLEDB','Server=.\MSSQL2016;TRUSTED_CONNECTION=YES;','exec sp_helpdb')
/*
Msg 11526, Level 16, State 1, Procedure sp_describe_first_result_set, Line 1
The metadata could not be determined because statement 'insert into #spdbdesc (dbname, owner, created, dbid, cmptlevel)
select name, isnull(suser_sname(s' in procedure 'sp_helpdb' uses a temp table.
*/
可以看出是因为不能确定所返回结果集的meta信息导致的：
EXEC sp_describe_first_result_set @tsql = N'exec msdb.dbo.sp_help_job'
GO
/*
Msg 11520, Level 16, State 1, Procedure sp_describe_first_result_set, Line 1
The metadata could not be determined because statement 'EXECUTE master.dbo.xp_sqlagent_is_starting @retval OUTPUT' in procedure 'sp_is_sqlagent_starting' invokes an extended stored procedure.
*/
变通的解决办法：自定义SP对需要调用的系统SP包装一次，用WITH RESULT SETS返回固定的结果集，从而避免这个错误；
注意WITH RESULT SETS选项从SQL SERVER 2012起开始支持，实例如下：
USE MSDB
GO IF (EXISTS (SELECT *
FROM msdb.dbo.sysobjects
WHERE (name = N'sp_help_job_with_results')
AND (type = 'P')))
DROP PROCEDURE sp_help_job_with_results
go
CREATE PROCEDURE sp_help_job_with_results
@job_id UNIQUEIDENTIFIER = NULL,
@job_name SYSNAME = NULL,
@job_aspect VARCHAR(9) = NULL,
@job_type VARCHAR(12) = NULL,
@owner_login_name SYSNAME = NULL,
@subsystem NVARCHAR(40) = NULL,
@category_name SYSNAME = NULL,
@enabled TINYINT = NULL,
@execution_status INT = NULL,
@date_comparator CHAR(1) = NULL,
@date_created DATETIME = NULL,
@date_last_modified DATETIME = NULL,
@description NVARCHAR(512) = NULL
AS
BEGIN
-- If job_id or job_name were not specified there will be only one resultset
IF (@job_id IS NULL AND @job_name IS NULL)
BEGIN
EXEC sp_help_job @job_id,
@job_name,
@job_aspect,
@job_type,
@owner_login_name,
@subsystem,
@category_name,
@enabled,
@execution_status,
@date_comparator,
@date_created,
@date_last_modified,
@description
WITH RESULT SETS
(
(
job_id UNIQUEIDENTIFIER,
originating_server NVARCHAR(30),
name SYSNAME,
[enabled] TINYINT,
[description] NVARCHAR(512),
start_step_id INT,
category SYSNAME,
[owner] SYSNAME,
notify_level_eventlog INT,
notify_level_email INT,
notify_level_netsend INT,
notify_level_page INT,
notify_email_operator SYSNAME,
notify_netsend_operator SYSNAME,
notify_page_operator SYSNAME,
delete_level INT,
date_created DATETIME,
date_modified DATETIME,
version_number INT,
last_run_date INT,
last_run_time INT,
last_run_outcome INT,
next_run_date INT,
next_run_time INT,
next_run_schedule_id INT,
current_execution_status INT,
current_execution_step SYSNAME,
current_retry_attempt INT,
has_step INT,
has_schedule INT,
has_target INT,
[type] INT
)
)
END
ELSE
BEGIN
-- If job_id or job_name is not null, there will be multiple resultsets
EXEC sp_help_job @job_id,
@job_name,
@job_aspect,
@job_type,
@owner_login_name,
@subsystem,
@category_name,
@enabled,
@execution_status,
@date_comparator,
@date_created,
@date_last_modified,
@description
WITH RESULT SETS
(
(
job_id UNIQUEIDENTIFIER,
originating_server NVARCHAR(30),
name SYSNAME,
[enabled] TINYINT,
[description] NVARCHAR(512),
start_step_id INT,
category SYSNAME,
[owner] SYSNAME,
notify_level_eventlog INT,
notify_level_email INT,
notify_level_netsend INT,
notify_level_page INT,
notify_email_operator SYSNAME,
notify_netsend_operator SYSNAME,
notify_page_operator SYSNAME,
delete_level INT,
date_created DATETIME,
date_modified DATETIME,
version_number INT,
last_run_date INT,
last_run_time INT,
last_run_outcome INT,
next_run_date INT,
next_run_time INT,
next_run_schedule_id INT,
current_execution_status INT,
current_execution_step SYSNAME,
current_retry_attempt INT,
has_step INT,
has_schedule INT,
has_target INT,
[type] INT
),
(
step_id INT,
step_name SYSNAME,
subsystem NVARCHAR(40) ,
command NVARCHAR(max) ,
flags NVARCHAR(4000),
cmdexec_success_code INT,
on_success_action NVARCHAR(4000),
on_success_step_id INT,
on_fail_action NVARCHAR(4000),
on_fail_step_id INT,
[server] SYSNAME,
database_name SYSNAME,
database_user_name SYSNAME,
retry_attempts INT,
retry_interval INT,
os_run_priority NVARCHAR(4000),
output_file_name NVARCHAR(200),
last_run_outcome INT,
last_run_duration INT,
last_run_retries INT,
last_run_date INT,
last_run_time INT,
proxy_id INT
),
(
schedule_id INT,
schedule_name SYSNAME,
[enabled] INT,
freq_type INT,
freq_interval INT,
freq_subday_type INT,
freq_subday_interval INT,
freq_relative_interval INT,
freq_recurrence_factor INT,
active_start_date INT,
active_end_date INT,
active_start_time INT,
active_end_time INT,
date_created DATETIME,
schedule_description NVARCHAR(4000) ,
next_run_date INT,
next_run_time INT,
schedule_uid UNIQUEIDENTIFIER,
job_count INT
),
(
server_id INT,
server_name NVARCHAR(30),
enlist_date DATETIME,
last_poll_date DATETIME,
last_run_date INT,
last_run_time INT,
last_run_duration INT,
last_run_outcome TINYINT,
last_outcome_message NVARCHAR(1024)
)
)
END
END
GO
sp_help_job_with_results
IF (EXISTS (SELECT *
FROM sysobjects
WHERE (name = 'sp_fixeddrives')
AND (type = 'P')))
DROP PROCEDURE sp_fixeddrives
GO CREATE PROCEDURE sp_fixeddrives
AS
BEGIN
EXEC xp_fixeddrives
WITH RESULT SETS
(
(
drive varchar(10),
[MB Free] varchar(100)
)
)
END
sp_fixeddrives
调用封装过的SP：
SET FMTONLY OFF
EXEC sp_describe_first_result_set @tsql = N'exec msdb.dbo.sp_help_job_with_results'
GO
EXEC sp_describe_first_result_set @tsql = N'exec sp_fixeddrives'
GO --直接调用sp_help_job失败
SELECT * FROM
OPENROWSET('SQLOLEDB','Server=.\MSSQL2016;TRUSTED_CONNECTION=YES;','exec msdb.dbo.sp_help_job')
--封装为sp_help_job_with_results后调用成功
SELECT * FROM
OPENROWSET ('SQLOLEDB','Server=.\MSSQL2016;Trusted_Connection=yes','EXEC msdb.dbo.sp_help_job_with_results') --直接调用xp_fixeddrives失败
SELECT * FROM
OPENROWSET('SQLOLEDB','Server=.\MSSQL2016;TRUSTED_CONNECTION=YES;','exec xp_fixeddrives') --封装为sp_fixeddrives后调用成功
SELECT * FROM
OPENROWSET('SQLOLEDB','Server=.\MSSQL2016;TRUSTED_CONNECTION=YES;','exec sp_fixeddrives')