SQL Server

Using EXISTS (or not EXISTS) will generally improve the efficiency of the query, because the NOT in clause performs a full table traversal of the tables in the subquery.During the execution of the in subquery, Oracle executes the subquery results

Read the doctor from a database, to the B Database Timing Alert table, filter has been read to the IDSELECTa.ID doctor's order Id, A.medordtype category, A.inhosid hospitalization number, A.execofficeid department code, a.starttime start time,

declare  @Level  INT=3; With cte_parent (Categoryid,categoryname,parentcategoryid,level) as (    SELECT  category_id,category_name,parent_category_id,1 as level    from  Tianshenlogistic.dbo.productcategory with (NOLOCK) where category_id in (SELECT 

View System LogsSELECT * FROM Sys.tracesView SQL Profile dump file First, use SQL profile to monitor the database and export it to TRC. Copy to the database server, EG.D:\SQLDATA\TRACE\201611290881.TRC The following statement in the

This article mainly shares the process of transaction execution in SQL Server.Note that this is only about the process, not the lock information, the information about the lock, there will be a special article to discuss later.The execution flow of

1 --1. Disable all triggers on a table2 ALTER TABLETbname DISABLETRIGGER All3 Go4 --2. Execute the UPDATE statement5 UpdateTbnameSet ....6 Go7 --3. Restore all triggers on a table8 ALTER TABLETbname ENABLETRIGGER All9 GoTrigger definition: It is

ObjectiveThis article is intended to help users of SQL Server databases understand common problems. and high-speed solutions to these problems. These issues are a general management problem for the database and provide an approximate FAQ framework

Functions commonly used to intercept strings in SQL Server:1.LEFT (character_expression, integer_expression) function Description: Left (' source string ', ' the number of characters to intercept leftmost ') returns the specified number of

If the size of the database design is too large, the database will still consume a large amount of disk resources even if large amounts of data are deleted from the database. Therefore, the database needs to be shrunk according to the actual needs

The database optimization consists of the following three parts, the optimization of database itself, the optimization of database table and the optimization of program operation. This article is Part IIIDatabase Performance Optimization Three:

SELECT * FROM master.dbo.sysprocesseswhere db_name (dbid) = ' Test 'and spid<>@ @SPIDLook at the blocking process.and kill it.EXEC (' kill ' [email protected])Because I am a remotely connected database, the kill process is always a concern. So I

ALTER PROC [dbo]. [AAA](@AgencyID int,--Reseller ID@AdminID INT--settlement operator ID (Administrator ID))AsBeginSelect Top 5 * from TusersReturn 5End$dbh = DB::connection()-getpdo(); $stmt = prepare("EXEC aaa?,?" $DBH );

Open function--to-allow advanced options to be changed.EXEC sp_configure ' show advanced options ', 1GO--To update the currently configured value for advanced options. RECONFIGUREGO--to enable the feature. EXEC sp_configure ' xp_cmdshell ', 1GO--To

SelectValue fromTf_njvalues ('3c457a2d-188b-4d99-a822-2968054e1fb8,3c457a2d-188b-4d99-a822-2968054e1fb8')CREATE FUNCTIONTf_njvalues (@P0 varchar(Max)--characters that need to be intercepted) RETURNS @OUT_TABLE TABLE(ValueVARCHAR(Max)) as BEGIN

SQL Injection tool_dynamic node: School of Java, sqljava BSQL Hacker 10 SQL Injection tools BSQL Hacker is developed by the Portcullis lab. BSQL Hacker is an automatic SQL injection tool that supports SQL blind injection. It is designed to cause

Why does SQL Server Alert send fewer alarm emails? Recently, we suddenly found the alarm (Alert) deployed on the database. When an error occurs in the error log, not every error log will be sent by email. As shown in the following figure, the alarm "

SQL server builds a method to execute dynamic SQL statements, serversql 1: Common SQL statements can be executed using exec Select * from tableName exec ('select * from tablename') exec sp_executesql N 'select * from tablename' -- note that N must

SqlServer converts query results to XML, JSON, and sqlserverjson I used it a long time ago. Now I have compiled some code from the Internet, but some bugs have been modified by me. 1. Convert query results to XML DECLARE @ParameterSQL NVARCHAR(MAX)='

MSSQL batch insert Data Optimization details, mssql insert Requirement One requirement is to insert 10 million pieces of data into the MSSQL database. The table structure is as follows. How long does it take you to insert 10 million pieces of data

Principles and Applications of SQL Server Indexes Index concept The purpose of indexing: Data Query and processing speed has become a benchmark for measuring the success or failure of the application system. Using indexes to speed up data processing