所有最常用的SQL命令语句大全

sql最全的常用命令语句 询某个数据库的连接数 select count(*) from Master.dbo.SysProcesses where dbid=db_id() --前10名其他等待类型 SELECT TOP 10 * from sys.dm_os_wait_stats ORDER BY wait_time_ms DESC SELECT *FROM sys.dm_os_wait_stats WHERE wait_type like 'PAGELATCH%' OR wait_type like 'LAZYWRITER_SLEEP%' --CPU的压力 SELECT scheduler_id, current_tasks_count, runnable_tasks_count FROM sys.dm_os_schedulers WHERE scheduler_id < 255 --表现最差的前10名使用查询 SELECT TOP 10 ProcedureName = t.text, ExecutionCount = s.execution_count, AvgExecutionTime = isnull ( s.total_elapsed_time / s.execution_count, 0 ), AvgWorkerTime = s.total_worker_time / s.execution_count, TotalWorkerTime = s.total_worker_time, MaxLogicalReads = s.max_logical_reads, MaxPhysicalReads = s.max_physical_reads, MaxLogicalWrites = s.max_logical_writes, CreationDateTime = s.creation_time, CallsPerSecond = isnull ( s.execution_count / datediff ( second , s.creation_time, getdate ()), 0 ) FROM sys.dm_exec_query_stats s CROSS APPLY sys.dm_exec_sql_text( s.sql_handle ) t ORDER BY s.max_physical_reads DESC SELECT SUM(signal_wait_time_ms) AS total_signal_wait_time_ms总信号等待时间 , SUM(wait_time_ms - signal_wait_time_ms) AS resource_wait_time_ms资源的等待时间, SUM(signal_wait_time_ms) * 1.0 / SUM (wait_time_ms) * 100 AS [signal_wait_percent信号等待％], SUM(wait_time_ms - signal_wait_time_ms) * 1.0 / SUM (wait_time_ms) * 100 AS [resource_wait_percent资源等待％] FROM sys.dm_os_wait_stats --一个信号等待时间过多对资源的等待时间那么你的CPU是目前的一个瓶颈。 --查看进程所执行的SQL语句 if (select COUNT(*) from master.dbo.sysprocesses) > 500 begin select text,CROSS APPLY master.sys.dm_exec_sql_text(a.sql_handle) from master.sys.sysprocesses a end select text,a.* from master.sys.sysprocesses a CROSS APPLY master.sys.dm_exec_sql_text(a.sql_handle) where a.spid = '51' dbcc inputbuffer(53) with tb as ( select blocking_session_id, session_id,db_name(database_id) as dbname,text from master.sys.dm_exec_requests a CROSS APPLY master.sys.dm_exec_sql_text(a.sql_handle) ), tb1 as ( select a.*,login_time,program_name,client_interface_name,login_name,cpu_time,memory_usage*8 as 'memory_usage(KB)', total_scheduled_time,reads,writes,logical_reads from tb a inner join master.sys.dm_exec_sessions b on a.session_id=b.session_id ) select a.*,connect_time,client_tcp_port,client_net_address from tb1 a inner join master.sys.dm_exec_connections b on a.session_id=b.session_id --当前进程数 select * from master.dbo.sysprocesses order by cpu desc --查看当前活动的进程数 sp_who active --查询是否由于连接没有释放引起CPU过高 select * from master.dbo.sysprocesses where spid> 50 and waittype = 0x0000 and waittime = 0 and status = 'sleeping ' and last_batch < dateadd(minute, -10, getdate()) and login_time < dateadd(minute, -10, getdate()) --强行释放空连接 select 'kill ' + rtrim(spid) from master.dbo.sysprocesses where spid> 50 and waittype = 0x0000 and waittime = 0 and status = 'sleeping ' and last_batch < dateadd(minute, -60, getdate()) and login_time < dateadd(minute, -60, getdate()) --查看当前占用 cpu 资源最高的会话和其中执行的语句(及时CPU) select spid,cmd,cpu,physical_io,memusage, (select top 1 [text] from ::fn_get_sql(sql_handle)) sql_text from master..sysprocesses order by cpu desc,physical_io desc --查看缓存中重用次数少，占用内存大的查询语句（当前缓存中未释放的）--全局 SELECT TOP 100 usecounts, objtype, p.size_in_bytes,[sql].[text] FROM sys.dm_exec_cached_plans p OUTER APPLY sys.dm_exec_sql_text (p.plan_handle) sql ORDER BY usecounts,p.size_in_bytes desc SELECT top 25 qt.text,qs.plan_generation_num,qs.execution_count,dbid,objectid FROM sys.dm_exec_query_stats qs CROSS APPLY sys.dm_exec_sql_text(sql_handle) as qt WHERE plan_generation_num >1 ORDER BY qs.plan_generation_num SELECT top 50 qt.text AS SQL_text ,SUM(qs.total_worker_time) AS total_cpu_time, SUM(qs.execution_count) AS total_execution_count, SUM(qs.total_worker_time)/SUM(qs.execution_count) AS avg_cpu_time, COUNT(*) AS number_of_statements FROM sys.dm_exec_query_stats qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) as qt GROUP BY qt.text ORDER BY total_cpu_time DESC --统计总的CPU时间 --ORDER BY avg_cpu_time DESC --统计平均单次查询CPU时间 -- 计算可运行状态下的工作进程数量 SELECT COUNT(*) as workers_waiting_for_cpu,s.scheduler_id FROM sys.dm_os_workers AS o INNER JOIN sys.dm_os_schedulers AS s ON o.scheduler_address=s.scheduler_address AND s.scheduler_id<255 WHERE o.state='RUNNABLE' GROUP BY s.scheduler_id