Using PostgreSQL in C #

I. C # connect PostgreSQL

1. To access the PostgreSQL database, you need to download the npgsql. Net Data Provider for PostgreSQL component from the Pgfoundry Web site.
Access url:http://pgfoundry.org/frs/?group_id=1000140 Note: Because Net4.0 is used, Npgsql-2.2.3-net40.zip is downloaded.

2. Unzip the zip file, copy the Npgsql.dll and Mono.Security.dll files to the packages directory in the C # project directory, and add to the references.

3. In the C # file header that needs to use Npgsql, add the following using statement: Using Npgsql;

Second, use

　2.1 Connection string

1, in the configuration file configuration method: The configuration file to add the following statement:

<!-- The database IP address, port number, database name, database logon name, password to access. Encountered garbled plus encoding-->

<connectionStrings>

<add name= "Postgre" connectionstring= "PORT=5432;DATABASE=DEMO; Host=localhost; Password=root; USER id=postgres "/>
</connectionStrings>

Get the connection string in the configuration file in code: string connstr =configurationmanager.connectionstrings["Postgre"]. ToString ();

  2, methods configured in code:  
  String constr  = @ "Port=5432;database=demo; Host=localhost; Password=root; USER id=postgres ";    
 
 2.2 Establish connection  
  npgsqlconnection sqlconn = new Npgsqlconnection (CONSTR); 
  
 2.3 use DataAdapter query to return a dataset  
 

  public  DataSet ExecuteQuery (string  Span style= "COLOR: #000000" > Sqrstr) {DataSet ds  = new   DataSet ();  try   { using  (npgsqldataadapter sqldap = new   Npgsqldataadapter (Sqrstr, sqlconn)) {Sqldap.                Fill (DS);             return   DS;             catch   (System.Exception ex)            {CloseConnection (); }}      

2.4 Adding and pruning operations

 Public intExecuteNonQuery (stringsqrstr) {            Try{sqlconn.open (); using(Npgsqlcommand SqlCommand =NewNpgsqlcommand (Sqrstr, sqlconn)) {                    intR = SqlCommand.ExecuteNonQuery ();//executes the query and returns the number of rows affectedSqlconn.close (); returnR//R If the >0 operation is successful!                 }                            }            Catch(System.Exception ex) {closeconnection (); return 0; }                            }

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2.5 Back to DataReader query

         PublicDbDataReader ExecuteReader (CommandType cmdtype,stringCmdtext)            {Sqlconn.open (); Try            {                using(Npgsqlcommand cmd =NewNpgsqlcommand (cmdtext);) {Npgsqldatareader SDR=cmd.                               ExecuteReader (commandbehavior.closeconnection); returnSDR; }                                        }            Catch{closeconnection (); return NULL; }        }  

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Using PostgreSQL in C #