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抛出错误提示 |
DECLARE @s VARCHAR(10); DECLARE @d INT; SET @s = 'P20100518001269' SET @d = 12; RAISERROR ('订单:%s不存在商品Id:%d' , 16, 1,@s,@d) WITH NOWAIT; |
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try_cach事务 |
-- try cath 写法 BEGIN TRANSACTION; BEGIN TRY /*更新语句*/ COMMIT TRANSACTION; END TRY BEGIN CATCH ROLLBACK TRANSACTION; SELECT ERROR_MESSAGE() AS [错误的描述]; END CATCH; |
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另外一个开事务的方法 |
/* 当SET XACT_ABORT 为ON 时，如果执行Transact-SQL 语句产生运行时错误，则整个事务将终止并回滚。 当SET XACT_ABORT 为OFF 时，有时只回滚产生错误的Transact-SQL 语句，而事务将继续进行处理。如果错误很严重，那么即使SET XACT_ABORT 为OFF，也可能回滚整个事务。 */ -- 简单写法 SET XACT_ABORT ON BEGIN TRAN /*更新语句*/ COMMIT TRAN |
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按关键字搜索存储过程、函数。 |
SELECT definition FROM sys.sql_modules WHERE PATINDEX('%t_orderpackage%',definition) > 0; |
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查询含有某字段的所有表 |
SELECT a.[name] AS [表名],b.[name] AS [字段名],b.length AS [字段长度],c.[name] AS [字段类型] FROM sys.sysobjects a -- sys.tables JOIN sys.syscolumns b ON a.id = b.id LEFT JOIN sys.systypes c ON b.xusertype = c.xusertype WHERE a.xtype='u' AND b.[name] LIKE '%CategoryId%'; |
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查看数据库返回的错误信息 |
SELECT * FROM sys.messages WHERE message_id = 102; |
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处理自动增长字段 |
-- 给自动增长字段付值 SET IDENTITY_INSERT [t_test] ON INSERT INTO t_test(id,[Name])VALUES(4,'fan'); SET IDENTITY_INSERT [t_test] OFF |
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每个表的行数 |
SELECT OBJECT_NAME([object_id]) AS table_name,b.rows AS 行数 FROM sys.tables AS a INNER JOIN sys.sysindexes AS b ON a.[object_id] = b.id WHERE b.indid IN(0,1) AND b.[rows] > 0; |
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判断中文 |
PATINDEX('%[吖-座]%',name)>0 |
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查看某个表的索引情况 |
-- 查看索引的使用情况、碎片率，采用系统的表值函数 SELECT index_type_desc,avg_fragmentation_in_percent,avg_fragment_size_in_pages, b.[NAME],object_name(a.object_id) FROM sys.dm_db_index_physical_stats(DB_ID(),OBJECT_ID('CM_ShippingList'),NULL,NULL,NULL) AS a JOIN sys.indexes AS b ON a.object_id = b.object_id AND a.index_id = b.index_id AND b.[NAME] > ''; |
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观察索引的使用情况 |
/*用语句查看索引的使用情况 sys.dm_db_index_physical_stats sys.dm_db_index_operational_stats*/ SELECT OBJECT_NAME(a.object_id) AS [表或视图名称], b.name AS [索引名称], b.type_desc AS [索引类型], a.user_seeks AS [索引查找次数], a.user_scans AS [索引扫描次数], a.user_lookups AS [索引书签查找次数], a.user_updates AS [索引更新次数], a.last_user_seek AS [用户上次查找时间], a.last_user_scan AS [用户上次扫描时间], a.last_user_lookup AS [用户上次书签查找的时间], a.last_user_update AS [用户上次修改索引的时间] FROM sys.dm_db_index_usage_stats -- 索引使用统计 a JOIN sys.indexes b -- 索引信息 ON a.OBJECT_ID = b.OBJECT_ID and a.index_id = b.index_id JOIN sys.objects c -- 对象信息 ON a.OBJECT_ID = c.OBJECT_ID AND c.type IN('V','U')-- 表或视图 WHERE a.database_id = DB_ID() AND a.index_id > 0 -- DB_ID()为当前库 ORDER BY [表或视图名称],[索引类型];
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查出缺失的索引 |
/*缺失索引功能使用动态管理对象和显示计划， 提供有关可增强SQL Server 查询性能的缺失索引的信息。 但要切记只是为我们创建有效的索引提供参考。是否需要创建还是要根据实际情况。*/ SELECT [statement] AS table_name, column_id, column_name, column_usage, mid.equality_columns,mid.included_columns FROM sys.dm_db_missing_index_details AS mid CROSS APPLY sys.dm_db_missing_index_columns (mid.index_handle) INNER JOIN sys.dm_db_missing_index_groups AS mig ON mig.index_handle = mid.index_handle WHERE mid.database_id=DB_ID() ORDER BY mig.index_group_handle, mig.index_handle, column_id; /*[说明] 如果是创建包含索引（覆盖索引）: Equality数据列排在左边 INEquality数据列排在后面 include数据列放在include子句后面
将选择性最高的数据行放在最前面 equality_columns: 这个字段和一个相等运算符在WHERE从句中使用。所以SQL Server告诉我们这将是针对索引的很好的选择。 included_columns: 索引创建时，其它可能被用作内嵌的字段。返回列。 */ |
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获取产生阻塞的语句 |
-- 获取产生阻塞的源头 DECLARE @sp_id sysname; SELECT |
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查看最耗I/O的语句 |
-- 查询最耗I/O资源的SQL语句 SELECT top 5 (total_logical_reads/execution_count) AS 平均逻辑读取次数, (total_logical_writes/execution_count) AS 平均逻辑写入次数, (total_physical_reads/execution_count) AS 平均物理读取次数, execution_count AS 执行次数, SUBSTRING(qt.text,r.statement_start_offset/2 + 1, (CASE WHEN r.statement_end_offset = -1 THEN DATALENGTH(qt.text) ELSE r.statement_end_offset END - r.statement_start_offset)/2 +1) AS 执行语句, DB_NAME(dbid),[text] FROM sys.dm_exec_query_stats AS r CROSS APPLY sys.dm_exec_sql_text(r.sql_handle) AS qt ORDER BY (total_logical_reads + total_logical_writes) DESC; |
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查看最耗CPU的语句 |
/*呈现最耗cpu的前个执行计划*/ SELECT TOP 50 total_worker_time/1000000.0 AS [总耗cpu时间(s)], execution_count AS [执行次数], qs.total_worker_time/qs.execution_count/1000000.0 AS [平均耗cpu时间(s)], SUBSTRING(qt.text,qs.statement_start_offset/2+1, (CASE WHEN qs.statement_end_offset = -1 THEN DATALENGTH(qt.text) ELSE qs.statement_end_offset END -qs.statement_start_offset)/2 + 1) AS [使用cpu的语句], qt.text AS [完整语句], qt.dbid, dbname = DB_NAME(qt.dbid), qt.objectid, OBJECT_NAME(qt.objectid) AS objectName FROM sys.dm_exec_query_stats qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS qt ORDER BY total_worker_time DESC; |
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查看最耗时间的语句 |
SELECT creation_time N'语句编译时间' ,last_execution_time N'上次执行时间' ,total_physical_reads N'物理读取总次数' ,total_logical_reads/execution_count N'每次逻辑读次数' ,total_logical_reads N'逻辑读取总次数' ,total_logical_writes N'逻辑写入总次数' ,execution_count N'执行次数' ,total_worker_time/1000 N'所用的CPU总时间ms' ,total_elapsed_time/1000 N'总花费时间ms' ,(total_elapsed_time / execution_count)/1000 N'平均时间ms' ,SUBSTRING(st.text, (qs.statement_start_offset/2) + 1, ((CASE statement_end_offset WHEN -1 THEN DATALENGTH(st.text) ELSE qs.statement_end_offset END - qs.statement_start_offset)/2) + 1) N'执行语句' FROM sys.dm_exec_query_stats AS qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) st where SUBSTRING(st.text, (qs.statement_start_offset/2) + 1, ((CASE statement_end_offset WHEN -1 THEN DATALENGTH(st.text) ELSE qs.statement_end_offset END - qs.statement_start_offset)/2) + 1) not like '%fetch%' ORDER BY total_elapsed_time / execution_count DESC; |