dynamic query in sql server

Sometimes you will need the function of SQL result set row to columnFor SQL row-to-column (PIVOT) and column-changing (UNPIVOT), refer to Https://www.cnblogs.com/linJie1930906722/p/6036714.htmlBut sometimes it takes a dynamic column and the data part of the presentation is a string using the method above does not make theFor example, to turn the top half of the p

files/Microsoft SQL Server/mssql10.mssqlserver/MSSQL/data/mydb. mdf d:/program files/Microsoft SQL Server/mssql10.mssqlserver/MSSQL/data/mydb_log.ldf (2 rows affected) */-- 3.2 mobile path use [Master] Go -- 3.2.1 disable all processes declare @ STR varchar (500); Set @ STR = ''; select @ STR = @ STR + 'Kill '+ rtrim

Tags: detail statement null entity NET SDN MyBatis class resulthttp://blog.csdn.net/yanggaosheng/article/details/46685565 mybatis MyBatis the dynamic SQL statement to complete a multi-condition query

Auxiliary classes1 usingSystem;2 usingSystem.Collections.Generic;3 usingSystem.Linq;4 usingSystem.Linq.Expressions;5 usingSystem.Text;6 usingSystem.Threading.Tasks;7 8 namespaceDrision.Framework.Logic.NYZF9 {Ten Public Static classPredicatebuilder One { A Public StaticExpressionBOOL>> truereturnf =true; } - Public StaticExpressionBOOL>> falsereturnf =false; } - the Public StaticExpressionBOOL>> or ThisExpressionBOOL>>Expr1, -ExpressionBOOL>>expr2) - {

In the process of paging data using temporary tables, it is found that the query statement conditions are passed through the stored procedure parameters. The parameter conditions cannot be directly used after the SQL where statements are added. There is only one solution to this problem, it is to concatenate SQL statements and conditions into an

row within the result set partition. The rank of a row is a number of rows before the line involved. --like here I sort by price, take out the most expensive items in each category from top to bottom SELECT * from ( SELECTI.price,i.commodityname,c.classname,rank () Over(Partition byC.classidOrder byI.priceDESC) Rank2 fromCommodityinfo iINNER JOINCommodityclass C onI.commodityclass=C.classid) RWHERERank22; Under SQL

the data is consistent, but nothing is perfect. The cost of the Begin Tran is that all the resources locked by the SQL statements cannot be released until the commit is committed before committing.It can be seen that if the BEGIN TRAN too many SQL statements, the performance of the database is poor. Before this large transaction commits, it is bound to block other statements, resulting in many blocks.The p

In this series of articles, we'll delve into how to combine the. NET 2.0 and SQL Server 2005 query notification features to inform the application when critical data changes in order to eliminate the recurring query database. First, the introduction One of the typical problems with database applications is updating sta

query uses the dynamic splicing of SQL statements. Query method is the most commonly used 1, the total number of data 2, data paging. Directly on the code (some conditions).Select Numb=count (Distinct t1.tlntcode) from ZWOMMAINM0 t1 inner joins ZWOMMLIBM0 T2 on T1.tlntcode=t2.tlntcode join ZW OMEXPRM0 CP on T1.tlntco

To analyze the performance of a query, you can view {Tagshow (event, '% D6 % B4 % D0 % D0 % BC % C6 % BB % AE ');} "Href =" javascript:; "target =" _ Self ">Execution Plan. Execution Plan description {Tagshow (event, 'SQL ');} "Href =" javascript:; "target =" _ Self ">SQL{Tagshow (event, 'server ');} "Href =" javascrip

. For example, when multiple indexes are used, the SELECT query may run faster. However, the speed of DML (insert, update, and delete) operations will be significantly slowed down because more indexes must be maintained for each operation. Therefore, if your query mainly contains select statements, it is very helpful to use more indexes. If your applicationProgramTo perform many DML operations, it is necess

that SQL Server Enterprise Manager performs.To use SQLDMO.DLL in asp.net2005, first register this component. To register the SQLDMO.DLL component:1. "Item"-"Add Reference"-"COM"--"SQLDMO". DLL "So you can register the SQLDMO.DLL component.2. SQLDMO.DLL files in the dynamic-link library under C:\Program Files\Microsoft SQL