Help using C# application to connect to oracle database

Question

I'm new to database.
I'm developing a C# GUI application in visual studio 2008 that is suppose to interact with oracle. After researching and trying out several sample codes, nothing works and I'm in desperate need of some help/advice/suggestions.
The simplest example I'm trying is to just get a button to run a simple SQL query. The code is:
private void button1_Click(object sender, EventArgs e)
string oradb = "Data Source=acme.gatech.edu;User Id=gtg880f;Password=******;";
OracleConnection conn = new OracleConnection(oradb); // C#
conn.Open();
OracleCommand cmd = new OracleCommand();
cmd.Connection = conn;
cmd.CommandText = "select Location_Name from warehouse where Location_name = 'atlanta'";
cmd.CommandType = CommandType.Text;
OracleDataReader dr = cmd.ExecuteReader();
dr.Read();
label1.Text = dr.GetString(0);
conn.Dispose();
I've installed many many version of oracle database and have included the Oracle.Data.Access under reference.
If I use putty and connect to acme.gatech.edu via port 22, I can type sqlplus / and run the query "elect Location_Name from warehouse where Location_name = 'atlanta'" and it'll work.
After some research, some say that if I can connect via sqlplus that means i can connect to the database but what do i need to implement to enable my c# code in visual studio to be able to do that.
I did a search on the forum but found nothing that matches this. In essence, I'm not sure what/how to specify such that I can connect to the acme.gatech.edu server and run sql commands.
Thanks,
Oky Sabeni

Answer 1

There're two ways you can get data in and out of database using .NET
#1 System.Data.OracleClient namespace - it's .NET avail out of the box
#2 Oracle.DataAccess.Client - aka "ODP.NET"
               Download: http://www.oracle.com/technology/software/tech/windows/odpnet/index.html
Or download Beta because as of today it's the only version which supports .NET "TransactionScope" (I just tested seems like still it is NOT working Re: 10g Express + ODP.NET (version 2.111.6.20) > support TransactionScope? http://www.oracle.com/technology/software/tech/windows/odpnet/index1110710beta.html
QuickStart: http://www.installationwiki.org/ODP.NET_Getting_Started_Guide
Also there's a doc under Start menu>Programs>Oracle - OraOdac11g_BETA_home>Application Development>"Oracle Data Provider for .NET Developer's Guide"
It's worth reading just scroll down quick for code fragment.
Anyway here's two small examples:
Example 1: System.Data.OracleClient (Using library from M$)
          * First you'll need to add reference to "System.Data.OracleClient".
          IDbFactory oDbFactory = DbProviderFactories.GetFactory("System.Data.OracleClient");
          IDbConnection oConn = oDbFactory.CreateConnection();
          oConn.ConnectionString = "Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=MyHost)(PORT=MyPort))(CONNECT_DATA=(SERVICE_NAME=MyOracleSID)));User Id=myUsername;Password=myPassword;";
          // Or ...
          oConn = new System.Data.OracleClient.OracleConnection("Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=MyHost)(PORT=MyPort))(CONNECT_DATA=(SERVICE_NAME=MyOracleSID)));User Id=myUsername;Password=myPassword;");
     Example 2: ODP.NET from Oracle
          IDbFactory oDbFactory = DbProviderFactories.GetFactory("Oracle.DataAccess.Client");
          IDbConnection oConn = oDbFactory.CreateConnection();
          oConn.ConnectionString = "Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=MyHost)(PORT=MyPort)))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=MyOracleSID)));User Id=myUsername;Password=myPassword;";
          // Or ...
          oConn = new Oracle.DataAccess.Client.OracleConnection("Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=MyHost)(PORT=MyPort)))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=MyOracleSID)));User Id=myUsername;Password=myPassword;");
string strSQL = "... SQL statement...";
          int nPersonId = 0;
          string strFirstName = null;
          Person oPerson = null;
          string strSQL = "SELECT Id FROM PERSON";
          oCmd = oConn.CreateCommand();
          oCmd.CommandText = strSQL;
          oCmd.CommandType = System.Data.CommandType.Text;
          IDataReader oRdr = oCmd.ExecuteReader();
          while (oRdr.Read())
               if (!Convert.IsDBNull(oRdr["Id"]))
                    nPersonId = (int) oRdr["Id"];
               if (!Convert.IsDBNull(oRdr["FirstName"]))
                    strFirstName = (string)oRdr["FirstName"];
               oPerson.Id = nPersonId;
               oPerson.FirstName = strFirstName;
Example CREATE TABLE:
          DECLARE
          count_item int;
          BEGIN
               SELECT count(1) into count_item FROM user_sequences WHERE sequence_name = 'AUDITLOGSEQUENCE';
               IF count_item > 0 THEN
                    begin
                    dbms_output.put_line('drop sequence AUDITLOGSEQUENCE');
                    EXECUTE IMMEDIATE ('DROP SEQUENCE AUDITLOGSEQUENCE');
                    end;
               ELSE
                    dbms_output.put_line('no need to drop AUDITLOGSEQUENCE');
               END IF;
               EXECUTE IMMEDIATE 'CREATE SEQUENCE AUDITLOGSEQUENCE
                    MINVALUE 1
                    MAXVALUE 999999999999999999999999999
                    START WITH 1
                    INCREMENT BY 1
                    CACHE 20';
               dbms_output.put_line('AUDITLOGSEQUENCE created');
               SELECT count(1) into count_item FROM user_tables WHERE table_name = 'LOG';
               IF count_item > 0 THEN
                    begin
                    dbms_output.put_line('drop table LOG');
                    EXECUTE IMMEDIATE ('DROP TABLE LOG');
                    end;
               ELSE
                    dbms_output.put_line('no need to drop table LOG');
               END IF;
               EXECUTE IMMEDIATE '
                    CREATE TABLE LOG (
                         Id numeric(19,0) NOT NULL,
                         CreateDate timestamp default sysdate NOT NULL,
                         Thread varchar (510) NULL,
                         LogLevel varchar (100) NULL,
                         Logger varchar (510) NULL,
                         Message varchar (4000) NULL,
                         InnerException varchar (4000) NULL,
                         CONSTRAINT PK_LOG PRIMARY KEY (Id)
               COMMIT;
               dbms_output.put_line('table LOG created');
               dbms_output.put_line('setup complete');
          EXCEPTION
               WHEN OTHERS THEN
                    dbms_output.put_line('*** setup exception detected! ***');
                    dbms_output.put_line('error code: ' || sqlcode);
                    dbms_output.put_line('stack trace: ' || dbms_utility.format_error_backtrace);
                    RAISE_APPLICATION_ERROR(-20000, 'AuditTrail.oracle.tables.sql - install failed');
          END;
     Before running script, make sure your account has permission (unless you're using SYS account of course). You'd probably need to know how to create user and granther right:
          CREATE USER dev IDENTIFIED BY "devacc_@";
          GRANT CREATE SESSION TO DEV;
          GRANT DBA TO DEV;
     Here's how you can run PL\SQL scripts in Oracle
     SQL*Plus: Release 10.2.0.1.0 - Production on Mon Apr 6 14:10:05 2009
          Copyright (c) 1982, 2005, Oracle. All rights reserved.
          SQL> connect devvvy/"somepwd"
          Connected.
          SQL> set serveroutput on
          SQL> @C:\dev\UnitTest\Util\Command\sql\Oracle\SetupSchema\xxxxx.oracle.tables.sql
          1125 /
          SQL> @C:\dev\Util\Command\sql\Oracle\SetupSchema\xxxxx.oracle.tables.data.only.sql
          560 /
          PL/SQL procedure successfully completed.
          SQL> @C:\dev\Util\Command\sql\Oracle\SetupSchema\AuditTrail.oracle.tables.sql
          54 /
          PL/SQL procedure successfully completed.
          SQL> COMMIT;
     Remeber however:
          (a) SQL*Plus does not like "&" in your SQL script. Do comment or string containing "&" should be taken out.
          (b) password should not contain "@" because it's a special character in "CONNECT" command.
               Alternative, download TOAD for Oracle - http://www.toadsoft.com/toad_oracle.htm
          (c) After command, type "/" next line to get command executed.
          (d) remember to COMMIT
REF for Oracle:
     Oracle Official doc: http://www.oracle.com/pls/db111/portal.portal_db?selected=1&frame=
     Oracle 11g configuration Guide: http://www.thegeekstuff.com/2008/10/oracle-11g-step-by-step-installation-guide-with-screenshots/
     ODAC/ODP.NET QuickStart: http://www.installationwiki.org/ODP.NET_Getting_Started_Guide
     ODP.NET versioning scheme: http://download.oracle.com/docs/html/E10927_01/InstallVersioningScheme.htm
     SQLPlus basic: http://download.oracle.com/docs/cd/B25329_01/doc/appdev.102/b25108/xedev_sqlplus.htm#CJAGGHGE
     PL\SQL:
          Cheat sheet: http://en.wikibooks.org/wiki/Oracle_Programming/SQL_Cheatsheet
          Reference:
               http://www.rocket99.com/techref/oracle_plsql.html
               http://download-uk.oracle.com/docs/cd/B19306_01/appdev.102/b14261/toc.htm
          EXECUTE IMMEDIATE, DROP/CREATE TABLE: http://www.java2s.com/Code/Oracle/PL-SQL/Callexecuteimmediatetodroptablecreatetableandinsertdata.htm
          Exception handling: http://download.oracle.com/docs/cd/B10501_01/appdev.920/a96624/07_errs.htm
          Named Block syntax: http://www.java2s.com/Tutorial/Oracle/0440__PL-SQL-Statements/Thestructureofanamedblock.htm
          CREATE PROCEDURE: http://it.toolbox.com/blogs/oracle-guide/learn-plsql-procedures-and-functions-13030
     Oracle DataType: http://www.ss64.com/orasyntax/datatypes.html
                         http://www.adp-gmbh.ch/ora/misc/datatypes/index.html
     Oracle Sequence and Create table: http://www.java2s.com/Tutorial/Oracle/0100__Sequences/Usingasequencetopopulateatablescolumn.htm