存储过程使用表变量或临时表代替游标Fetch实例，访问远程数据库

定义表变量是可以直接操作在内存中的数据，比较快。临时表在大数据量时会比游标使用的资源少。还是要看具体情况了。也有可能在实际优化过程中相互替换呢。

留作记忆的代码如下：

 if object_id('tempdb..#Tmp') is not null
 Begin
     drop table #Tmp
 End

         create table #Tmp  --创建临时表#Tmp为获取远程设备信息使用
         (
             deviceId varchar(50),
             deviceNo varchar(200),
             FlagID   TINYINT
         );
 declare @i int,--执行一条sql语句的临时变量,用于远程数据库配置信息循环
         @j int,--执行一条sql语句的临时变量，用于更新设备信息名称
         @user varchar(50),--用户名
         @password varchar(100),--密码
         @ssid varchar(100),--ssid
         @db varchar(100),--数据库名称
         @server varchar(100),--远程数据库server
         @database varchar(200),
         @remoteid int
 --定义远程数据库配置信息临时表
 declare @tRemoteOffice table
         (
             RemoteId int,
             RomoteUser varchar(50),
             RemotePassword varchar(100),
             RemoteSsid varchar(100),
             RemoteDb varchar(100),
             RemoteName varchar(100),
             FlagID   TINYINT
         )

         begin

         BEGIN TRY---------------------开始捕捉异常

         --1.查询远程数据库配置表，插入查询数据到临时表
         insert @tRemoteOffice select remote_id, remote_user,remote_psw,remote_ssid,remote_database,remote_name,0 from dbo.RemoteDBInfo;
         print CONVERT(varchar(100), GETDATE(),21)+'插入远程数据库配置信息到临时表，一共执行'+convert(varchar(5),@@ROWCOUNT)+'条'

         set @i=1;
         --Return_connectError:
         while(@i>=1)
             begin
             Return_begin:
             --2.选取临时表里的一条数据
             SELECT TOP 1 @remoteid=RemoteId, @user = RomoteUser,@password=RemotePassword,@ssid=RemoteSsid,@db=RemoteDb,@server=RemoteName FROM @tRemoteOffice  WHERE FlagID=0;
             SET @i=@@ROWCOUNT
             IF @i<=0 GOTO Return_Lab
             print '开始连接远程数据库,ssid:'+@ssid;
             begin try
             --3.连接远程数据库
             exec   sp_addlinkedserver     @server, ' ', 'SQLOLEDB', @ssid ;
             exec   sp_addlinkedsrvlogin   @server, 'false ',null, @user, @password ;

             select @database=@server+'.'+@db;
             --4.查询远程数据库的机构信息
             declare @officeID nvarchar(50),
                     @officeName nvarchar(200)

             declare @searchRemoteOfficeSql Nvarchar(max)=N'SELECT @Id=office_id,@Name=office_name FROM  '+@database+'.dbo.Office where caste=0';
             Exec sp_executesql @searchRemoteOfficeSql,N'@Id nvarchar(50) output,@Name nvarchar(100) output',@officeID output,@officeName output;

             print CONVERT(varchar(100), GETDATE(),21)+'查询远程数据库机构信息，一共执行'+convert(varchar(5),@@ROWCOUNT)+'条'
             update dbo.RemoteDBInfo set remote_type=1 WHERE remote_ssid = @ssid ;
             end try
             begin catch
                 print '连接远程数据库'+@ssid+'异常'
                 exec sp_dropserver  @server, 'droplogins ';
                 UPDATE @tRemoteOffice SET FlagID=1 WHERE RemoteSsid = @ssid;
                 update dbo.RemoteDBInfo set remote_type=0 WHERE remote_ssid = @ssid ;
                 goto Return_begin
             end catch
             --5.查询已连接的远程数据库officeid是否已在本地表中
             declare @SearchLocalUnitySql Nvarchar(max)=N'select UnityId from dbo.Unity where UnityId =@Id ';
             Exec sp_executesql @SearchLocalUnitySql,N'@Id nvarchar(50)',@Id=@officeID;

             --6.不在本地表中，插入新的机构信息
             if @@ROWCOUNT=0
                 begin

                 declare @InsertUnityOfficeSql Nvarchar(max)=N'insert into dbo.Unity (UnityId,Name,ParentId,Type,remote_id) values(@id,@name,NULL,0,@remote_id) ';
                 Exec sp_executesql @InsertUnityOfficeSql,N'@id nvarchar(50),@name nvarchar(200),@remote_id int',@id=@officeID,@name=@officeName,@remote_id=@remoteid;
                 print CONVERT(varchar(100), GETDATE(),21)+'插入新的机构信息，一共执行'+convert(varchar(5),@@ROWCOUNT)+'条'
                 end
             --7.在本地表中，更新机构名称
             else
                 begin
                 declare @UpdateUnityOfficeNameSql Nvarchar(max)=N'update dbo.Unity set Name=@Name1,remote_id=@remote_id where UnityId=@Id1 ';
                 Exec sp_executesql @UpdateUnityOfficeNameSql,N'@Name1 nvarchar(100),@Id1 nvarchar(50),@remote_id int',@Name1=@officeName,@Id1=@officeID,@remote_id=@remoteid;
                 print CONVERT(varchar(100), GETDATE(),21)+'更新机构信息，一共执行'+convert(varchar(5),@@ROWCOUNT)+'条'
                 end

             --8.插入设备信息到临时表
             truncate table #Tmp
             declare @deviceID varchar(50),
                     @deviceName varchar(200)

             declare @InsertRemoteDeviceSql Nvarchar(max)=N'insert #Tmp select device_id,device_no,0 FROM  '+@server+'.'+@db+'.dbo.device where parent_id is null and is_bom=0 and status=1 ';
             Exec sp_executesql @InsertRemoteDeviceSql;
             print CONVERT(varchar(100), GETDATE(),21)+'插入设备信息到临时表，一共执行'+convert(varchar(5),@@ROWCOUNT)+'条'
             set @j=1;
             while(@j>=1)
                 begin
                 --9.选取临时表里的一条数据
                 SELECT TOP 1 @deviceID = deviceId,@deviceName=deviceNo FROM #Tmp  WHERE FlagID=0;
                 SET @j=@@ROWCOUNT
                 IF @j<=0 GOTO Return_device
                 --10.查询临时表里的deviceId是否在Unity里
                 declare @SearchLocalUnityDeviceSql Nvarchar(max)=N'select UnityId from dbo.Unity where UnityId =@id ';
                 Exec sp_executesql @SearchLocalUnityDeviceSql,N'@id nvarchar(50)',@id=@deviceID;
                 --@@ROWCOUNT被执行一次后清零
                 --print CONVERT(varchar(100), GETDATE(),21)+'查询临时表里的设备id是否在Unity里，一共执行'+convert(varchar(5),@@ROWCOUNT)+'条'
                 --11.不在表数据里，插入新的设备信息
                 if    @@ROWCOUNT=0
                     begin

                     declare @InsertUnityDeviceSql Nvarchar(max)=N'insert into dbo.Unity (UnityId,Name,ParentId,Type) values (@id,@name,@parentid,1) ';
                     Exec sp_executesql @InsertUnityDeviceSql,N'@id nvarchar(50),@name nvarchar(200),@parentid nvarchar(50)',@id=@deviceID,@name=@deviceName,@parentid=@officeID;
                     print CONVERT(varchar(100), GETDATE(),21)+'插入新的设备信息，一共执行'+convert(varchar(5),@@ROWCOUNT)+'条'
                     end
                 --12.在表数据里，更新设备名称
                 else
                     begin
                     declare @UpdateUnityDeviceNameSql Nvarchar(max)=N'update dbo.Unity set Name=@name where UnityId=@id ';
                     Exec sp_executesql @UpdateUnityDeviceNameSql,N'@name nvarchar(200),@id nvarchar(50)',@name=@deviceName,@id=@deviceID;
                     print CONVERT(varchar(100), GETDATE(),21)+'更新设备名称，一共执行'+convert(varchar(5),@@ROWCOUNT)+'条'
                     end

                 --13.获取本地FireReport表的最新数据时间
                 declare @fireReportTime DateTime
                 declare @SearchFireReportTime Nvarchar(max)=N'SELECT top 1 @time=FindTime FROM dbo.FireReport where UnityId=@id order by FindTime desc';
                 Exec sp_executesql @SearchFireReportTime,N'@time Datetime output,@id nvarchar(50)',@fireReportTime output,@id=@deviceID;
                 --14.插入火情信息数据
                 if @fireReportTime=null
                     begin
                     set @fireReportTime=GETDATE();
                     end

                     --0 未处理，1确认，2误报，3取消，4上报，5未知状态
                     declare @InsertFireSql Nvarchar(max)=N'insert into dbo.FireReport(FindTime,FireType,UnityId)
                                                             select raised_dt
                                                             ,CASE WHEN confirmed = 0 and cancelled=0 and discarded=0 and reported=0  THEN 0
                                                             WHEN confirmed = 1 and cancelled=0 and discarded=0 and reported=0 THEN 1
                                                             WHEN confirmed = 0 and cancelled=0 and discarded=1 and reported=0 THEN 2
                                                             WHEN confirmed = 0 and cancelled=3 and discarded=0 and reported=0 THEN 3
                                                             WHEN confirmed = 0 and cancelled=0 and discarded=0 and reported=4 THEN 4
                                                             ELSE 5 END,@id FROM  '+@server+'.'+@db+'.dbo.fire where raised_dt>@time and  tower_id=@id order by raised_dt desc';
                     Exec sp_executesql @InsertFireSql,N'@id nvarchar(50),@time DateTime',@id=@deviceID,@time=@fireReportTime;
                     print CONVERT(varchar(100), GETDATE(),21)+'.插入火情信息数据，一共执行'+convert(varchar(5),@@ROWCOUNT)+'条'

                 --15.插入设备状态数据
                 --首先判断在视图中是否存在设备运行状态
                 declare @SearchViewSql Nvarchar(max)=N'SELECT tower_id  FROM  '+@server+'.'+@db+'.dbo.vw_cruise_state where tower_id=@id ';
                 Exec sp_executesql @SearchViewSql,N'@id nvarchar(50)',@id=@deviceID;
                 if @@ROWCOUNT>0
                     begin
                     declare @InsertDeviceStatusSql Nvarchar(max)=N'Insert into dbo.DeviceStatus(UnityID,GetTime,Status) SELECT  tower_id,GETDATE(),aa_status  FROM  '+@server+'.'+@db+'.dbo.vw_cruise_state where tower_id=@id ';
                     Exec sp_executesql @InsertDeviceStatusSql,N'@id nvarchar(50)',@id=@deviceID;
                     print CONVERT(varchar(100), GETDATE(),21)+'插入设备运行状态数据，一共执行'+convert(varchar(5),@@ROWCOUNT)+'条';
                     print CONVERT(varchar(100), GETDATE(),21)+'设备ID为：'+@deviceID;
                     end        

                 IF @@error=0
                     UPDATE #Tmp SET FlagID=1 WHERE deviceId = @deviceID 

                 Return_device:
                 end
                 truncate table #Tmp;

             exec sp_dropserver  @server, 'droplogins ';
             IF @@error=0
                 UPDATE @tRemoteOffice SET FlagID=1 WHERE RemoteSsid = @ssid  

             Return_Lab:
             end
         DROP TABLE [dbo].#Tmp

         END TRY-----------结束捕捉异常

         BEGIN CATCH------------有异常被捕获
         print @@error;
         --IF @@TRANCOUNT > 0---------------判断有没有事务
         --BEGIN
         --    ROLLBACK TRAN----------回滚事务
         --END
             print ERROR_MESSAGE();
             UPDATE @tRemoteOffice SET FlagID=1 WHERE RemoteSsid = @ssid;
             exec sp_dropserver  @server, 'droplogins '; -----------执行存储过程将错误信息记录在表当中
         END CATCH--------结束异常处理

         end