C uses ODP.net to connect to the Oracle database

This article describes the process of connecting C# to the Oracle database. With instant client and ODP.DataAccess.dll in net, you can easily deploy.net applications or sites without having to install the Oracle client. So let's talk about the 1 process.

1. Installation of ODAC
Download the version of ODAC that corresponds to the version of oracle you installed from oracle's official website.
Download address: ODAC Download
After downloading and unzip the installation, you don't need to install all the components. The following components are mainly installed:
Oracle Instant Client
Oracle Data Provider For .net2.0
Oracle rovider For Asp .net

2. Setting environment variables
Set the environment variable of Windows:
ORACLE_HOME: Installation directory for ODAC (similar to ~ \app\Administrator\product\11.1.0\client_1);
ORACLE_HOME LD_LIBRARY_PATH: % %;
ORACLE_HOME TNS_ADMIN: % %;
Append to the front of PATH: %ORACLE_HOME%;

3. Listen to the configuration file tnsnames.ora
In the directory %ORACLE_HOME%, create a new file tnsnames.ora, which reads as follows:

 
 The database SID = 
(DESCRIPTION = 
(ADDRESS_LIST = 
(ADDRESS = (PROTOCOL = TCP)(HOST = Oracle Host name or IP)(PORT = 1521)) 
) 
(CONNECT_DATA = 
(SERVICE_NAME =  The database SID) 
) 
) 

4. plsqldev
With this configuration, plsqldev can connect to the oracle database.

5. C# connect Oracle
The sample code for C# to connect oracle is as follows:

 
OracleConnection conn = 
new OracleConnection(); 
try 
{ 
conn.ConnectionString = ConfigurationManager.ConnectionStrings["oradb"].ConnectionString; 
conn.Open(); 
string sql = " select id,content from test"; // C# 
OracleCommand cmd = new OracleCommand(sql, conn); 
cmd.CommandType = CommandType.Text; 
OracleDataReader dr = cmd.ExecuteReader(); // C# 
List<string> contents = newList<string>(); 
while(dr.Read()) 
{ 
contents.Add(dr["content"].ToString()); 
} 
listBox1.ItemsSource = contents; 
} 
catch(Exception ex) 
{ 
MessageBox.Show(ex.Message); 
} 
finally 
{ 
conn.Clone(); 
} 

Appends the configuration of the database connection to the program ES81en.config or ES83en.config.

 
<connectionStrings > 
<add name="oradb"connectionString="Data Source=(DESCRIPTION= 
(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.1.1)(PORT=1521))) 
(CONNECT_DATA=(SERVICE_NAME=****))); 
User Id=***;Password=***;"/> 
</connectionStrings> 

Follow these steps and, if there are no errors, you can successfully connect to the database.