wordpress模块化建站,丁香园做科室网站,提高网站用户体验,网站安全在线检测一.修改语句的增强UPDATE test SET tname.WRITE(one hundred and two, 9, 3) WHERE tid 102在2005中增强了update方法#xff0c;这是修改test表的列tname WRITE方法是把tname这个列中从字符串9开始 把3个长的字符串改为one hundred and two二、异常的捕获可以捕获过去会导致…一.修改语句的增强UPDATE test SET tname.WRITE(one hundred and two, 9, 3) WHERE tid 102在2005中增强了update方法这是修改test表的列tname WRITE方法是把tname这个列中从字符串9开始 把3个长的字符串改为one hundred and two二、异常的捕获可以捕获过去会导致批处理终止和事务的错误但是不能处理连接中断错误和硬件错误等--Using the try..catch.. construct and invoking a run-time errorSET XACT_ABORT of 这个打开捕获异常的开关 默认是关闭的BEGIN TRY BEGIN TRAN INSERT INTO score VALUES (102,78) INSERT INTO score VALUES (107, 76) /**//* Foreign Key Error */ INSERT INTO score VALUES (103,81) COMMIT TRAN PRINT Transaction committedEND TRYBEGIN CATCH ROLLBACK PRINT Transaction rolled back SELECT ERROR_NUMBER() AS ErrorNumber, ERROR_SEVERITY() AS ErrorSeverity, ERROR_STATE() as ErrorState, ERROR_MESSAGE() as ErrorMessage;END CATCHGO三、快照隔离写入程序不会影响读取程序可对事务冲突的检测create database demo2 建立数据库gouse demo2alter database demo2 set allow_snapshot_isolation on 打开快照隔离开关默认是关闭的create table test( tid int not null primary key, tname varchar(50) not null)insert into test values(1,version1)insert into test values(2,version2)--connection 1use demo2begin tran update test set tnameversion3 where tid2 select * from test--connection 2use demo2set transaction isolation level snapshotselect * from test--it will ok, you can see it 四 、top语句的增强可以是数字表达式一返回要通过通过查询影响的行输或者百分比还可以是更具情况使用变量和子查询可以在delete、update和insert中使用top选项更好的代替set rowcount选项使之更为有效。--create a table and insert some datause demogoCREATE TABLE toptest (column1 VARCHAR(150))goINSERT INTO toptest VALUES(t1)INSERT INTO toptest VALUES(t2)INSERT INTO toptest VALUES(t3)INSERT INTO toptest VALUES(t4)INSERT INTO toptest VALUES(t5)INSERT INTO toptest VALUES(t6)INSERT INTO toptest VALUES(t7)INSERT INTO toptest VALUES(t8)select * from toptestgoCREATE TABLE toptest2 (column2 VARCHAR(150))goINSERT INTO toptest2 VALUES(c1)INSERT INTO toptest2 VALUES(c2)--declare 3 variablesDECLARE a INTDECLARE b INTDECLARE c INT--set valuesSET a 10SET b 5SELECT c a/b--use the calculated expressionSELECT TOP(c) * FROM toptest--use a SELECT statement as expressionSELECT TOP(SELECT COUNT(*) FROM toptest2) * FROM toptest--DML topDELETE TOP(2) toptest where column1t6--this sets t1 and t2 to hiUPDATE TOP(2) toptest SET column1 hi where column1t2SELECT * FROM toptest五、output引入一个新的output字句 可以使您从修改语句elete、update和insert中将数据返回到表变量中语法output dml_select_list into table_variable可以通过应用插入的表和删除的表来访问被修改的行的旧/新映象起方式于访问触发器类似在insert语句中只能访问插入的表update和delete也一样。访问临时表--create table and insert datause demogoCREATE TABLE tt (id INT IDENTITY, c1 VARCHAR(15))goINSERT INTO tt VALUES (r1)INSERT INTO tt VALUES (r2)INSERT INTO tt VALUES (r5)INSERT INTO tt VALUES (r6)INSERT INTO tt VALUES (r7)INSERT INTO tt VALUES (r8)INSERT INTO tt VALUES (r9)INSERT INTO tt VALUES (r10)--make a table variable to hold the results of the OUTPUT clauseDECLARE del AS TABLE (deletedId INT, deletedValue VARCHAR(15))DELETE ttOUTPUT DELETED.id, DELETED.c1 INTO delWHERE id 3SELECT * FROM delGO六、函数ROW_NUMBER是结果集的顺序, 而不是数据库中纪录存放的原始顺序SELECT orderid,qty, ROW_NUMBER() OVER(ORDER BY qty) AS rownumber, RANK() OVER(ORDER BY qty) AS rank, DENSE_RANK() OVER(ORDER BY qty) AS denserank FROM rankorderORDER BY qty七、通用表达式 cte 临时命名的结果集USE AdventureWorksGOWITH SalesCTE(ProductID, SalesOrderID)AS ( SELECT ProductID, COUNT(SalesOrderID) FROM Sales.SalesOrderDetail GROUP BY ProductID)SELECT * FROM SalesCTE------ Using CTEs Recursivelyuse demogoCREATE TABLE CarParts( CarID int NOT NULL, Part varchar(15), SubPart varchar(15), Qty int)GOINSERT CarParts VALUES (1, Body, Door, 4)INSERT CarParts VALUES (1, Body, Trunk Lid, 1)INSERT CarParts VALUES (1, Body, Car Hood, 1)INSERT CarParts VALUES (1, Door, Handle, 1)INSERT CarParts VALUES (1, Door, Lock, 1)INSERT CarParts VALUES (1, Door, Window, 1)INSERT CarParts VALUES (1, Body, Rivets, 1000)INSERT CarParts VALUES (1, Door, Rivets, 100)INSERT CarParts VALUES (1, Door, Mirror, 1)goselect * from CarPartsgoWITH CarPartsCTE(SubPart, Qty) AS( -- Anchor Member (AM): -- SELECT query that doesn’t refer back to CarPartsCTE SELECT SubPart, Qty FROM CarParts WHERE Part Body UNION ALL -- Recursive Member (RM): -- SELECT query that refers back to CarPartsCTE SELECT CarParts.SubPart, CarPartsCTE.Qty * CarParts.Qty FROM CarPartsCTE INNER JOIN CarParts ON CarPartsCTE.SubPart CarParts.Part WHERE CarParts.CarID 1)--outer querySELECT SubPart, SUM(Qty) AS TotalNUMFROM CarPartsCTEGROUP BY SubPart八、新的关系运算符pivot 把行转回为列unpivot 把列转回为行use demogocreate table orders(Customer varchar(10) not null, product varchar(20) not null, quantity int not null)goinsert orders values(Mike, Bike,3)insert orders values(Mike,Chain,2)insert orders values(Mike,Bike,5)insert orders values(Lisa,Bike,3)insert orders values(Lisa,Chain,3)insert orders values(Lisa,Chain,4)insert orders values(Lisa,Bike,2)select * from ordersselect * from orderspivot (sum(quantity) for product in ([Bike],[Chain])) as ause demogoCREATE TABLE SALES1([Year] INT,Quarter CHAR(2),Amount FLOAT)GOINSERT INTO SALES1 VALUES (2001, Q1, 80)INSERT INTO SALES1 VALUES (2001, Q2, 70)INSERT INTO SALES1 VALUES (2001, Q3, 55)INSERT INTO SALES1 VALUES (2001, Q3, 110)INSERT INTO SALES1 VALUES (2001, Q4, 90)INSERT INTO SALES1 VALUES (2002, Q1, 200)INSERT INTO SALES1 VALUES (2002, Q2, 150)INSERT INTO SALES1 VALUES (2002, Q2, 40)INSERT INTO SALES1 VALUES (2002, Q2, 60)INSERT INTO SALES1 VALUES (2002, Q3, 120)INSERT INTO SALES1 VALUES (2002, Q3, 110)INSERT INTO SALES1 VALUES (2002, Q4, 180)GOSELECT * FROM SALES1PIVOT(SUM (Amount) --Aggregate the Amount column using SUMFOR [Quarter] --Pivot the Quarter column into column headingsIN (Q1, Q2, Q3, Q4)) --use these quartersAS PGOselect * into temp1 from orderspivot (sum(quantity) for product in ([Bike],[Chain])) as aselect * from temp1select customer, product,quantityfroam temp1unpivot(quantity for product in ([Bike],[Chain])) as a九、ddl触发器use demogoCREATE TRIGGER prevent_drop_table ON DATABASE FOR DROP_TABLEASRAISERROR(Not allowed to drop tables., 10, 1)PRINT DROP TABLE attempt in database DB_NAME() .PRINT CONVERT (nvarchar (1000),EventData())ROLLBACKGO-- testCREATE TABLE TestDROP(col1 INT)goINSERT INTO TestDROP VALUES(1)drop talbe testdrop-- ServerCREATE TRIGGER audit_ddl_logins ON ALL SERVER FOR CREATE_LOGIN, ALTER_LOGIN, DROP_LOGINASPRINT DDL LOGIN took place.PRINT CONVERT (nvarchar (1000),EventData())GO-- testCREATE LOGIN login1 WITH PASSWORD 123ALTER LOGIN login1 WITH PASSWORD xyzDROP LOGIN login1 丰富的数据类型 Richer Data Types 1、varchar(max)、nvarchar(max)和varbinary(max)数据类型最多可以保存2GB的数据可以取代text、ntext或image数据类型。CREATE TABLE myTable( id INT, content VARCHAR(MAX))2、XML数据类型XML数据类型允许用户在SQL Server数据库中保存XML片段或文档。错误处理 Error Handling 1、新的异常处理结构2、可以捕获和处理过去会导致批处理终止的错误前提是这些错误不会导致连接中断通常是严重程度为21以上的错误例如表或数据库完整性可疑、硬件错误等等。。3、TRY/CATCH 构造SET XACT_ABORT ON BEGIN TRY core logic END TRY BEGIN CATCH TRAN_ABORT exception handling logic END TRYerror may be quired as first statement in CATCH block4、演示代码USE demo GO --创建工作表 CREATE TABLE student ( stuid INT NOT NULL PRIMARY KEY, stuname VARCHAR(50) ) CREATE TABLE score ( stuid INT NOT NULL REFERENCES student(stuid), score INT )GOINSERT INTO student VALUES (101,zhangsan) INSERT INTO student VALUES (102,wangwu) INSERT INTO student VALUES (103,lishi) INSERT INTO student VALUES (104,maliu) --调用一个运行时错误SET XACT_ABORT OFF BEGIN TRAN INSERT INTO score VALUES (101,90) INSERT INTO score VALUES (102,78) INSERT INTO score VALUES (107, 76) /**//* 外键错误 */ INSERT INTO score VALUES (103,81) INSERT INTO score VALUES (104,65) COMMIT TRAN GO SELECT * FROM student SELECT * FROM score--使用TRYCATCH构造并调用一个运行时错误SET XACT_ABORT OFF BEGIN TRY BEGIN TRAN INSERT INTO score VALUES (101,90) INSERT INTO score VALUES (102,78) INSERT INTO score VALUES (107, 76) /**//* 外键错误 */ INSERT INTO score VALUES (103,81) INSERT INTO score VALUES (104,65) COMMIT TRAN PRINT 事务提交 END TRY BEGIN CATCH ROLLBACK PRINT 事务回滚 SELECT ERROR_NUMBER() AS ErrorNumber, ERROR_SEVERITY() AS ErrorSeverity, ERROR_STATE() as ErrorState, ERROR_MESSAGE() as ErrorMessage; END CATCHGOSELECT * FROM scoreGO快照隔离 Snapshot Isolation1、写入程序不会阻碍读取程序2、Snapshot isolation must be enabled for DB ALTER DATABASE 数据库 SET allow_snapshot_isolation ON3、Snapshot isolation must be enabled for connection Set transaction isolation level snapshot4、UPDATE transactions keep old versions of data in a linked list5、新的隔离级别提供了以下优点 1) 提高了只读应用程序的数据可用性 2) 允许在OLTP环境中执行非阻止读取操作 3) 可对写入事务进行自动的强制冲突检测6、演示代码CREATE DATABASE demo2GOUSE demo2 ALTER DATABASE demo2 SET allow_snapshot_isolation ON CREATE TABLE test ( tid INT NOT NULL primary key, tname VARCHAR(50) NOT NULL ) INSERT INTO test VALUES(1,version1) INSERT INTO test VALUES(2,version2)--连接一USE demo2BEGIN TRAN UPDATE test SET tnameversion3 WHERE tid2 SELECT * FROM test--连接二USE demo2 SET transaction isolation level snapshot SELECT * FROM test TOP 增强功能1、TOP 增强可以指定一个数字表达式以返回要通过查询影响的行数或百分比还可以根据情况使用变量或子查询。可以在DELETE、UPDATE和INSERT查询中使用TOP选项。2、更好地替换SET ROWCOUNT选项使之更为有效。OUTPUT1、SQL Server 2005引入一个新的OUTPUT子句以使您可以冲修改语句(INSERT、UPDATE、DELETE)中将数据返回到表变量中。2、新的OUTPUT子局的语法为OUTPUT dml_select_list INTO table_variable可以通过引用插入的表或删除的表来访问被修改的行的旧/新影象其方式与访问触发器类似。在INSERT语句中只能访问插入的表。在DELETE语句中只能访问删除的表。在UPDATE语句中可以访问插入的表和删除的表。3、代码演示USE demoGOCREATE TABLE tt ( id INT IDENTITY, c1 VARCHAR(15))GOINSERT INTO tt VALUES (r1)INSERT INTO tt VALUES (r2)INSERT INTO tt VALUES (r5)INSERT INTO tt VALUES (r6)INSERT INTO tt VALUES (r7)INSERT INTO tt VALUES (r8)INSERT INTO tt VALUES (r9)INSERT INTO tt VALUES (r10)DECLARE del AS TABLE (deletedId INT, deletedValue VARCHAR(15))DELETE ttOUTPUT DELETED.id, DELETED.c1 INTO delWHERE id 3SELECT * FROM delGO-----------------------------------------------USE demoGOCREATE TABLE toptest (column1 VARCHAR(150))GOINSERT INTO toptest VALUES(t1)INSERT INTO toptest VALUES(t2)INSERT INTO toptest VALUES(t3)INSERT INTO toptest VALUES(t4)INSERT INTO toptest VALUES(t5)INSERT INTO toptest VALUES(t6)INSERT INTO toptest VALUES(t7)INSERT INTO toptest VALUES(t8)SELECT * FROM toptestGOCREATE TABLE toptest2 (column2 VARCHAR(150))GOINSERT INTO toptest2 VALUES(c1)INSERT INTO toptest2 VALUES(c2)--声明3个变量DECLARE a INTDECLARE b INTDECLARE c INT--赋值SET a 10SET b 5SELECT c a/b--使用计算表达式SELECT TOP(c) * FROM toptest--使用SELECT语句作为条件SELECT TOP(SELECT COUNT(*) FROM toptest2) * FROM toptest--指出topDELETE TOP(2) toptest where column1t6--更新topUPDATE TOP(2) toptest SET column1 hi where column1t2SELECT * FROM toptest排序函数 Ranking Functions1、SQL Server引入几个新的排序函数如ROW_NUMBER、RANK、DENSE_RANK等。这些新函数使您可以有效地分析数据以及向查询的结果行提供排序值。2、排序函数都遵循类似的语法模式()OVER([PARTITION BY]ORDER BY)该函数只能在查询的两个子句中指定 - 在SELECT子句或ORDER BY子句中。以下详细讨论不同的函数。 3、ROW_NUMBERROW_NUMBER是结果集的顺序, 而不是数据库中纪录存放的原始顺序USE demoGOCREATE TABLE rankorder( orderid INT, qty INT)GOINSERT rankorder VALUES(30001,10)INSERT rankorder VALUES(10001,10)INSERT rankorder VALUES(10006,10)INSERT rankorder VALUES(40005,10)INSERT rankorder VALUES(30003,15)INSERT rankorder VALUES(30004,20)INSERT rankorder VALUES(20002,20)INSERT rankorder VALUES(20001,20)INSERT rankorder VALUES(10005,30)INSERT rankorder VALUES(30007,30)INSERT rankorder VALUES(40001,40)GOSELECT orderid,qty, ROW_NUMBER() OVER(ORDER BY qty) AS rownumber, RANK() OVER(ORDER BY qty) AS rank, DENSE_RANK() OVER(ORDER BY qty) AS denserank FROM rankorderORDER BY qty通用表表达式 Common Table Expressions 通 用表表达式CTE是一个可以由定义语句引用的临时表命名的结果集。在他们的简单形式中您可以将CTE视为类似于视图和派生表混合功能的改进版本。在 查询的FROM子句中引用CTE的方式类似于引用派生表和视图的方式。只须定义CTE一次即可在查询中多次引用它。在CTE的定义中可以引用在同一批 处理中定义的变量。但是CTE的真正威力在于它们的递归功能即CTE可以包含对它们自身的引用。视图、派生表和CTE内部的查询的一般形式1、视图CREATE VIEW view_name(column_aliases) AS view_query2、派生表SELECT * FROM (derived_table)query) AS dericed_table_alias(column_aliases)3、CTEWITH cte_alias(column_aliases)AS{ cte_query)SELECT * FROM cte_alias]在关键字WITH之后为CTE提供一个别名并且为它的结果列提供一个可选的别名列表编写CTE的主体然后从外部查询中引用它。4、演示代码USE AdventureWorksGOWITH SalesCTE(ProductID, SalesOrderID)AS ( SELECT ProductID, COUNT(SalesOrderID) FROM Sales.SalesOrderDetail GROUP BY ProductID)SELECT * FROM SalesCTERecursive CTEs 递归的通用表表达式递归的CTE是根据至少两个查询或者称为两个成员构建的一个是非递归查询也成为固定成员只能调用一次另外一个是递归查询也成为递归成员RM可以反复调用直到查询不再返回行。查询由UNION ALL运算符连接为一个单独的CTE。--使用递归的通用表表达式USE demoGOCREATE TABLE CarParts( CarID INT NOT NULL, Part VARCHAR(15), SubPart VARCHAR(15), Qty INT)GOINSERT CarParts VALUES (1, Body, Door, 4)INSERT CarParts VALUES (1, Body, Trunk Lid, 1)INSERT CarParts VALUES (1, Body, Car Hood, 1)INSERT CarParts VALUES (1, Door, Handle, 1)INSERT CarParts VALUES (1, Door, Lock, 1)INSERT CarParts VALUES (1, Door, Window, 1)INSERT CarParts VALUES (1, Body, Rivets, 1000)INSERT CarParts VALUES (1, Door, Rivets, 100)INSERT CarParts VALUES (1, Door, Mirror, 1)GOSELECT * FROM CarPartsGOWITH CarPartsCTE(SubPart, Qty) AS( -- 固定成员 (AM): -- SELECT查询无需参考CarPartsCTE SELECT SubPart, Qty FROM CarParts WHERE Part Body UNION ALL -- 递归成员 (RM): -- SELECT查询参考CarPartsCTE SELECT CarParts.SubPart, CarPartsCTE.Qty * CarParts.Qty FROM CarPartsCTE INNER JOIN CarParts ON CarPartsCTE.SubPart CarParts.Part WHERE CarParts.CarID 1)-- 外部查询SELECT SubPart, SUM(Qty) AS TotalNUMFROM CarPartsCTEGROUP BY SubPart 新的关系运算符 PIVOT/UNPIVOT/APPLY1、PIVOTPIVOT运算符将行旋转为列并且可能同时执行聚合。使用PIVOT运算符时要注意的重要一点是需要为它提供一个查询表达式表达式使用视图、派生表或者是CTE只返回所关注的列。2、UNPIVOTUNPIVOT运算符执行与PIVOT运算符相反的操作他将列旋转为行了。3、APPLYAPPLY关系运算符允许您对外部表的每个行调用指定的表值函数一次。您可以在查询的FROM子句中指定APPLY其方式与使用JOIN关系运算符类似。APPLY具有两种形式CROSS APPLY和OUTER APPLY。演示USE demoGOCREATE TABLE orders( Customer VARCHAR(10) NOT NULL, product VARCHAR(20) NOT NULL, quantity INT NOT NULL)GOINSERT orders VALUES(Mike, Bike,3)INSERT orders VALUES(Mike,Chain,2)INSERT orders VALUES(Mike,Bike,5)INSERT orders VALUES(Lisa,Bike,3)INSERT orders VALUES(Lisa,Chain,3)INSERT orders VALUES(Lisa,Chain,4)INSERT orders VALUES(Lisa,Bike,2)SELECT * FROM ordersSELECT * FROM ordersPIVOT (SUM(quantity) FOR product IN ([Bike],[Chain])) AS aUSE demoGOCREATE TABLE SALES1( [Year] INT, Quarter CHAR(2), Amount FLOAT)GOINSERT INTO SALES1 VALUES (2001, Q1, 80)INSERT INTO SALES1 VALUES (2001, Q2, 70)INSERT INTO SALES1 VALUES (2001, Q3, 55)INSERT INTO SALES1 VALUES (2001, Q3, 110)INSERT INTO SALES1 VALUES (2001, Q4, 90)INSERT INTO SALES1 VALUES (2002, Q1, 200)INSERT INTO SALES1 VALUES (2002, Q2, 150)INSERT INTO SALES1 VALUES (2002, Q2, 40)INSERT INTO SALES1 VALUES (2002, Q2, 60)INSERT INTO SALES1 VALUES (2002, Q3, 120)INSERT INTO SALES1 VALUES (2002, Q3, 110)INSERT INTO SALES1 VALUES (2002, Q4, 180)GOSELECT * FROM SALES1PIVOT(SUM (Amount) --使用SUM聚合数量列FOR [Quarter] --PIVOT Quarter 列IN (Q1, Q2, Q3, Q4)) --使用季节AS PGOSELECT * INTO temp1 FROM ordersPIVOT (sum(quantity) FOR product IN ([Bike],[Chain])) AS aSELECT * FROM temp1SELECT customer, product,quantityFROM temp1UNPIVOT(quantity FOR product IN ([Bike],[Chain])) AS a----------------------------------------------------USE demoGOCREATE TABLE Arrays( aid INT NOT NULL IDENTITY PRIMARY KEY, array VARCHAR(7999) NOT NULL)GOINSERT INTO Arrays VALUES()INSERT INTO Arrays VALUES(10)INSERT INTO Arrays VALUES(20,40,30)INSERT INTO Arrays VALUES(-1,-3,-5)GOCREATE FUNCTION function1(arr AS VARCHAR(7999)) RETURNS t TABLE(pos INT NOT NULL, value INT NOT NULL)ASBEGIN DECLARE end AS INT, start AS INT, pos AS INT SELECT arr arr ,, pos 1, start 1, end CHARINDEX(,, arr, start) WHILE end 1 BEGIN INSERT INTO t VALUES(pos, SUBSTRING(arr, start, end - start)) SELECT pos pos 1, start end 1, end CHARINDEX(,, arr, start) END RETURNEND--测试SELECT * FROM function1(200,400,300)GOSELECT A.aid, F.*FROM Arrays AS A CROSS APPLY function1(array) AS FGOSELECT A.aid, F.*FROM Arrays AS A OUTER APPLY function1(array) AS FGODDL触发器 DDL TriggersSQL Server 2005 可以就整个服务器或数据库的某个范围为DDL事件定义触发器。也可以为单个DDL语句例如CREAT_TABLE、DROP_TABLE等或者为一 组语句例如指定DDL_DATABASE_LEVEL_EVENTS想要触发器触发数据库所有DDL事件定义DDL触发器。在DDL触发器内部可以通过访问eventdata()函数获得与激发该触发器的事件有关的数据。该eventdata()函数返回有关事件的xml数据。DDL触发器特别有用的方案包括DDL更改的完整性检查、审核方案以及其他方案。代码演示USE demoGOCREATE TRIGGER prevent_drop_table ON DATABASE FOR DROP_TABLEASRAISERROR(没有删除表的权限., 10, 1)PRINT 尝试在数据库 DB_NAME() 中删除表.PRINT CONVERT (nvarchar (1000),EventData())ROLLBACKGO-- 测试CREATE TABLE TestDROP(col1 INT)GOINSERT INTO TestDROP VALUES(1)DROP TABLE testdrop-- ServerCREATE TRIGGER audit_ddl_logins ON ALL SERVER FOR CREATE_LOGIN, ALTER_LOGIN, DROP_LOGINASPRINT 发生DDL LOGIN.PRINT CONVERT (nvarchar (1000),EventData())GO-- 测试CREATE LOGIN login1 WITH PASSWORD 123ALTER LOGIN login1 WITH PASSWORD xyzDROP LOGIN login1SQL Server 2005 在Transaction-SQL上所做的改进反映了其更好地满足了ANSI-99 SQL规范的要求以及客户的需求。 create proc [dbo].[Name_Add] Name varchar(50)asbeginbegin traninsert Names (Name)select (Name) where not exists (select NameId from Names with(HOLDLOCK) where Name Name)commit transelect NameId,Name from Names with(nolock) where Name Nameend 要点检查加锁插入值在一句sql中完成.这样再大的并发也不怕了.
