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As a small programmer, it is inevitable to deal with where in and like in daily development, in most cases, the parameters we pass are not much simple, single quotation marks, sensitive characters escape, and then directly spelled into the SQL, execute the query, done. If one day you inevitably need to improve the SQL query performance, and you need to place hundreds, thousands, or even tens of thousands of pieces of data at a time, parameterized query will be an inevitable choice. However, how

Using system; Using system. Data; Using system. Data. sqlclient; Namespace sysclasslibrary{/// /// Summary of dataaccess./// /// Public class dataaccess{# Region attributesProtected static sqlconnection conn = new sqlconnection ();Protected static sqlcommand comm = new sqlcommand ();# EndregionPublic dataaccess (){// Init ();}# The static method of region internal functions does not execute the dataaccess () constructor. /// // open the databa

Using System;Using System. Data;Using System. Data. SqlClient;Namespace SysClassLibrary{/// /// Summary of DataAccess./// /// Public class DataAccess{# Region attributesProtected static SqlConnection conn = new SqlConnection ();Protected static SqlCommand comm = new SqlCommand ();# EndregionPublic DataAccess (){// Init ();}# The static method of region internal functions does not execute the DataAccess () constructor./// /// Open the database connecti

As a little programmer, it is inevitable to deal with where in and like in daily development, in most cases, the parameters we pass are not much simple, single quotation marks, sensitive characters escape, and then directly spelled into the SQL, execute the query, done. If one day you inevitably need to improve the SQL query performance, and you need to place hundreds, thousands, or even tens of thousands of pieces of data at a time, parameterized query will be an inevitable choice. However, how

Original address:Http://www.cnblogs.com/lzrabbit/archive/2012/04/22/2465313.html In addition to validating the parameter contents, filter the length and SQL keywords.Resolving in-conditional stitching stringsComm.commandtext = "SELECT * from the Users (NOLOCK) where UserID in (@UserID1, @UserId2, @UserID3, @UserID4)"; Comm. Parameters.addrange ( new sqlparameter[]{ new SqlParameter ("@UserID1", SqlDbType.Int)

Copy codeThe Code is as follows:Public class SqlOperation{# Region attributes/// /// The connection string stored in Web. config/// Protected static string connectionstring = System. Configuration. ConfigurationManager. ConnectionStrings ["hao"]. ConnectionString;/// /// SqlConnection object/// Protected static SqlConnection conn = new SqlConnection ();/// /// SqlCommand object/// Protected static SqlCommand comm = new SqlCommand ();# Endregion# Regio

As a small program ape, in the daily development can not avoid to and where in and like to deal with, in most cases we pass the parameters of simple quotes, sensitive word escape directly after the SQL, execute the query, fix. If one day you inevitably need to improve SQL query performance, need a one-time where in hundreds of, thousands, or even tens of thousands of data, parameterized query will be the inevitable choice. However, how to implement the parameterized query of where in and like is

Using system; Using system. Collections. Generic; Using system. Windows. forms; Using system. Data. sqlclient; Using system. Data; Using system. serviceprocess; Namespace adminzjc. databasecontrol{/// /// Database Operation Control/// Public class databasecontrol{/// /// Database connection string/// Public String connectionstring; /// /// SQL statement/Stored Procedure/// Public String strsql; /// /// Instantiate a database connection object/// Private sqlconnection conn; /// /// Instantiate a

situation can meet the needsString userids = "1,2,3,4"; using (SqlConnection conn = new SqlConnection (connectionString)) { Conn. Open (); SqlCommand comm = new SqlCommand (); Comm. Connection = conn; Comm.commandtext = string. Format ("SELECT * from the Users (NOLOCK) where UserID in ({0})", userids); Comm. ExecuteNonQuery ();}An attempt to make

all, we commonly used methods, directly to the SQL implementation, the general situation can meet the needsString userids = "1,2,3,4"; using (SqlConnection conn = new SqlConnection (connectionString)) { Conn. Open (); SqlCommand comm = new SqlCommand (); Comm. Connection = conn; Comm.commandtext = string. Format ("SELECT * from the Users (NOLOCK) where UserID in ({0})", userids);

Follow the previous "One Promise Practice: Asynchronous Task grouping scheduling", this time is also from the work of the actual problems encountered.This encounter problem can be likened to a batch of raw materials processing, wherein the beginning of some of the process is the same, like the assembly line, the beginning of a paragraph is the same, the back is divided into two streams, on this basis, respectively, the production of different products. o--o--o Product 1

implementation, the general situation can meet the needs String userids = "1,2,3,4"; using (SqlConnection conn = new SqlConnection (connectionString)) { Conn. Open (); SqlCommand comm = new SqlCommand (); Comm. Connection = conn; Comm.commandtext = string. Format ("SELECT * from the Users (NOLOCK) where UserID in ({0})", userids); Comm. Exec

CopyCode The Code is as follows: public class sqloperation { # Region attributes /// /// The connection string stored in Web. config /// Protected static string connectionstring = system. configuration. configurationmanager. connectionstrings ["hao"]. connectionstring; /// /// Sqlconnection object /// Protected static sqlconnection conn = new sqlconnection (); /// /// Sqlcommand object /// Protected static sqlcommand comm = new sqlcommand (); # Endreg

As a small programmer, in the day-to-day development can not be avoided with where in and like to deal with, in most cases we pass the parameters of simple quotes, sensitive words escape directly after the SQL, execute the query, fix. If one day you inevitably need to improve SQL query performance, need a one-time where in hundreds of, thousands, or even tens of thousands of data, parameterized query will be the inevitable choice. However, how to implement the parameterized query of where in and

the SQL query performance, and you need to place hundreds, thousands, or even tens of thousands of pieces of data at a time, parameterized query will be an inevitable choice. However, how to implement the where in and like parameterized queries is a headache for many people. Implementation of where in parametric Query First of all, let's talk about the common method to implement SQL directly, which can meet the needs in general. String userIds = "1, 2, 4 "; Using (SqlConnection conn = new SqlCo

Http://www.systronix.com/book/tools/javaxcomm.html Javaxcomm installation and configuration problems are common. Everytime I configure a new PC it seems there is some new problem waiting to bite -- for instance, these: First, check your system environment If the events you tried to set up didn't really take place, then of course nothing will work as intended. typos in system environment variables are a simple example of what can go wrong. so before you get too worried, check yo

single value (query statement with parameters)public static Object Getscalar (String sql, params sqlparameter[] para){Try{Con. Open ();SqlCommand cmd = new SqlCommand (sql, con);Cmd. Parameters.addrange (para);return CMD. ExecuteScalar ();}catch (Exception ex){Throw ex;}Finally{Con. Close ();}} #region Stored Procedure Call method ////Invoke the parameter stored procedure to perform additions or deletions //////// public static int exectuecommandstoredprocedure (string name, params sqlparamete

. Internal connection, usually use the most, the simplest equals number connection example: There are two tables, assuming that A and B are many-to-one relationship a LEFT join B the number of records connected to a table with the number of recordsA Right JoinThe number of records connected to B is equal to the number of records connected in A and B plus the number of records on the B no matchThis way, you can understand the left join and right connections.A left Join BEquivalentB Right Join A.A

(SqlConnection conn = new SqlConnection (connectionString )){SqlCommand comm = new SqlCommand ();Comm. Connection = conn;Comm. CommandType = CommandType. Text;Comm. CommandText = sqlstr;Try{Conn. Open ();I = comm. ExecuteNonQuery ();}Catch (SqlException e){New ErrorLog ().

SQL server support functions for XML, mainly query (), nodes (), exist (), value (), modify (), see the http://msdn.microsoft.com/zh-cn/library/ms190798.aspx There are two ways to implement where in using XML: Value and exist. The exist method is recommended here, as described in msdn: D. Use the exist () method instead of the value () method. value () method in a predicate to compare with a relational value, use exist () with SQL: column () . "> for performance reasons, value () i