tsql nullif

the scope of their functionality, otherwise cascading deletions and cascading updates may make your data inexplicably modified or lost. cascading deletions and cascading updates are more efficient than other methods in terms of performance. Optimized ⑤: Proper use of stored procedures, views, functions Many people are accustomed to putting complex operations on the application layer, but if you want to optimize data access performance , porting SQL code to the database ( using stored procedur

steps.A) Create a new job. Such as:A, create a new job. Such as:b, click the General tab of the New Job dialog box and fill in the name of the SQL job. Such asC, click on the "Steps" tab of the "New Job" dialog box to complete the step name.D. The first step in the job------establish a database connection operation. Such as:E. The next step in the operation. Such as:E. Set the job execution planF, click OK to complete the SQL job development.G, after the completion of the job is more than just

Description: The Fmdb version is 2.5 and has not been modified.Indatabase, intransaction for dispatch_sync(_queue, ^ () {} operation. _queue = dispatch_queue_create([[nsstring stringwithformat:@ "fmdb.%@", Self ] utf8string], NULL); 0. To use transactions, you need to turn on:[self. Databasequeue indatabase: ^ (fmdatabase *db) { TResult = [db executeupdate:@ "PRAGMA Foreign_keys = on"]; if(!tresult) return ; }];The open transaction is essentially a query operation (pendin

specifiedIPAccess client) If SQL Server 2005 is used, you can also use the endpoint restriction method. This method requires a dedicated Nic, all clients that can connect to SQL Server are connected through this NIC (assuming the IP address of this Nic is 192.168.1.1 ): 1. In "SQL Server 2005 network configuration" of "SQL Server Configuration Manager", all protocols except TCP/IP are prohibited; 2. Disable the default TCP endpoint with the following T-SQL Alter endpoint [

applications, because SQL is only processed in one place.3. Using database objects to implement all TSQL helps to analyze TSQL performance problems, and helps you to centrally manage TSQL code and better reconstruct TSQL code.Optimization 6: The Legend of the Three Little principles' ①: The fewer tables in the databas

Dede the various methods of tag invocationDede tag the most common method of callingmethod of the latest tag tag call{dede:tag row= ' 30′sort= ' new '} [field:highlight/] ([field:result/]) {/dede:tag}the method of the month popular tag tag call{dede:tag row= ' 30′getall= ' 1′sort= ' Month '} [field:tagname/] ([field:result/]) {/dede:tag}method of random tag tag call{dede:tag row= ' 60′sort= ' Rand '} [field:highlight/] ([field:result/]) {/dede:tag}content Page Tag Add method of Tag call{dede:tag

· Express · Workgroup · Standard · Enterprise · Enterprise version Connectivity · SQL Server Management Studio · Sqlcmd · SQL Server 2008 R2 management Studio provides complete connectivity to SQL azure. Earlier versions have limited support. · Sqlcmd Data Migration · SQL server integration services, BCP, and sqlbulkcopyapi

number 1- A logical page number 8 . DBCC sqlmgrstats : These values are used to generate three different values. They are used in the ad-hoc and pre-compiled tsql statements you want to view how the cache works. Example: DBCC sqlmgrstats Result: item status ------------------------------------ Memory Used (8 K pages) 5446 Number csql objects 29098 Number false hits 425490 where: L Memor used (8 K pages): if the number of memory pages is very

Value QL> L 1 * select * From tsql> C/select/update 1 * update * From tsql> L 1 * update * From tsql> C/from/think 1 * update * think tsql> L 1 * update * think t B] edit editsql> editwrote file afiedt. buf 1 * update * think T C] displayList n displays the nth row in SQL Buffer and makes the nth row the current row.

number 8 . DBCC sqlmgrstats :These values are used to generate three different values. They are used in the ad-hoc and pre-compiled tsql statements you want to view how the cache works. Example: DBCC sqlmgrstats result: item status ------------------------------------ Memory Used (8 K pages) 5446 Number csql objects 29098 Number false hits 425490 where: l memor used (8 K pages): if the number of memory pages is very large, this may be a prompt: Some

token stream of data. microsoft does not document the actual TDS messages, as this is considered a private contract between SQL Server components. RPC message:The parameterized SQL and TSQL statements are used and submitted to SQL Server in RPC message mode. In contrast, the parameterized SQL statements are not used, which is called ad hoc SQL. Note the difference between SQL and TSQL. ad hoc SQL only refe

// to make the settings take effect. You can change the environment variable LD_LIBRARY_PATH to the configuration file/etc/lD. So. conf. Add/usr/local/freetds0.91/lib to the last line of the file. If the file/etc/lD. So. conf is changed, run ldconfig under the root user to make the configuration take effect immediately. If you have any questions about the configurations of these two variables, it is best to take a good look at this article: There is information on the Internet that I still need

realize the classification show friendship Connection Category Channel Call Friendship Connection Find you/behind/templets/friendlink_add.htm we modify the site type to The code is as follows Copy Code $dsql->setquery ("SELECT * from #@__arctype");$dsql->execute ();while ($row = $dsql->getobject ()){echo "}?> In this way, when you increase the friendship connection will show the classification of the site, then we want to classify the page how to call it

to solve the problem, starting with a new table DatabaseLog in the msdb database to hold the information that DDL triggers get. Where DDL triggers primarily return information about server or database events through the EVENTDATA () function. Copy Code code as follows: Use msdb; Go CREATE TABLE [dbo]. [DatabaseLog] ( [Databaselogid] [INT] IDENTITY (1,1) not NULL, [Posttime] [DateTime] Not NULL, [Databaseuser] [sysname] COLLATE SQL_Latin1_General_CP1_CI_AS not NULL, [LoginN

This article analyzes the SQL Server 2005 deep tools and run time sets. Simplified Development and debugging The tight integration of Microsoft Visual Studio with the. NET framework makes it easier to develop and debug data-driven application systems. Developers can build database objects, such as stored processes, using any. NET language and can be debugged seamlessly across the. NET and Transact-SQL (TSQL) languages. On the client side, effective

investigate why CPU utilization can rise to 100%. The steps for associating SQL Profiler trace information and performance counter logs are as follows: 1 Create performance counter logs that include the following common performance counters, specifying "manual" way to start and stop counter logs: --network interface \ Output Queue Length --processor \% processor Time --sql Server: Buffer manager \ buffer Cache Hit ratio --sql Server: Buffer manager \ Page life cycle --sql server:sql stat

network transmission, processing and storage, and are compiled and optimized to perform fast, easy to maintain, and when the structure of the table changes, does not affect the client's application 2. Using stored procedures, views, functions can help reduce the drawbacks of SQL replication in your application, because SQL is now centrally processed in only one place 3. Using database objects to implement all TSQL helps to analyze

* Power( -, (i-1)); EndLoop; return(To_char (Result));EndHextodec;View Code3. Dectohex function: Numeric string-to-hexadecimal stringCreate or Replace functionDecToHex (Idecimalinch varchar2)return varchar2 isNdecimalinteger; Quotientinteger; Residueinteger; Resultvarchar2( -);beginNdecimal:=To_number (Idecimal); Loop quotient:= Floor(Ndecimal/ -); Residue:=Ndecimal MoD -; SelectDecode (Residue,Ten,'A', One,'B', A,'C', -,'D', -,'E', the,'F', To_char (residue))||result intoResult from

Server useful resources. Of course, if you need to do it, you have to do it.When you know that the SELECT statement will never return duplicate records, use the DISTINCT statement to waste SQL Server resources unnecessarily.5. Use fewer cursors:Any kind of cursor can degrade SQL Server performance. Some situations cannot be avoided, and most of them can be avoided. So if your application is currently using a TSQL cursor, see if the code can be rewrit

General functions (learning notes), general function learning notes -- **************** Common functions-- NVL processing NULL-- NVL (number | column, default value). If the displayed number is NULL, the default value is used.-- NVL2 (number | column, default value: 1; default value: 2) if the column is not NULL, result 1 is returned. If it is NULL, result 2 is returned.-- NULLIF (expression 1, expression 2) comparison expression 1, and expression 2,