C# connecting to Oracle database
Petr Faltus development
OracleDBclient.cs
GitHub repository: oracle-database-connection-source-codes
git clone https://github.com/petrfaltus/oracle-database-connection-source-codes.git
Directories to OracleDBclient.cs in the repository: csharp
/*
1) Install 'Oracle Data Provider for .NET'
2) Check the right Oracle.ManagedDataAccess.dll from Oracle Data Provider for .NET in the bin subdirectory
*/
using System;
using System.Data;
using Oracle.ManagedDataAccess.Client;
public class OracleDBclient
{
private const string db_host = "localhost";
private const int db_port = 1521;
private const string db_srvname = "ORCLCDB.localdomain";
private const string db_username = "testuser";
private const string db_password = "T3stUs3r!";
private const string db_table = "cars";
private const string db_update_column = "remark";
private const string db_update_column_variable = "updatevar";
private const string db_column = "id";
private const string db_column_variable = "var";
private const int db_column_value = 1;
private const string db_factorial_variable = "n";
private const int db_factorial_value = 4;
private const string db_add_and_subtract_a_variable = "a";
private const int db_add_and_subtract_a_value = 12;
private const string db_add_and_subtract_b_variable = "b";
private const int db_add_and_subtract_b_value = 5;
private const string db_add_and_subtract_x_variable = "x";
private const string db_add_and_subtract_y_variable = "y";
private static string GetNow()
{
DateTime dateTimeNow = DateTime.Now;
return dateTimeNow.ToString();
}
public static void Main(string[] args)
{
// Build the connection string
OracleConnectionStringBuilder connBuilder = new OracleConnectionStringBuilder();
connBuilder.DataSource = String.Format("{0}:{1}/{2}", db_host, db_port, db_srvname);
connBuilder.UserID = db_username;
connBuilder.Password = db_password;
try
{
using (OracleConnection conn = new OracleConnection(connBuilder.ConnectionString))
{
// Connect the database
conn.Open();
Console.WriteLine("Data source: {0}", conn.DataSource);
Console.WriteLine("Server version: {0}", conn.ServerVersion);
Console.WriteLine("Connection timeout: {0}", conn.ConnectionTimeout);
Console.WriteLine("State: {0}", conn.State);
Console.WriteLine();
// UPDATE statement
string new_comment = "C# " + GetNow();
string sql0 = String.Format("update {0} set {1}=:{2} where {3}!=:{4}", db_table, db_update_column, db_update_column_variable, db_column, db_column_variable);
Console.WriteLine(sql0);
using (var cmd = new OracleCommand(sql0, conn))
{
OracleParameter par1 = new OracleParameter(db_update_column_variable, new_comment);
cmd.Parameters.Add(par1);
OracleParameter par2 = new OracleParameter(db_column_variable, db_column_value);
cmd.Parameters.Add(par2);
int updatedRows = cmd.ExecuteNonQuery();
Console.WriteLine("Total updated rows: {0}", updatedRows);
}
Console.WriteLine();
// Full SELECT statement
string sql1 = String.Format("select * from {0}", db_table);
Console.WriteLine(sql1);
using (var cmd = new OracleCommand(sql1, conn))
using (OracleDataReader reader = cmd.ExecuteReader())
{
int columns = reader.FieldCount;
Console.WriteLine("Total columns: {0}", columns);
for (int ii = 0; ii < columns; ii++)
{
Console.WriteLine(" - {0} {1}", reader.GetName(ii), reader.GetDataTypeName(ii));
}
int number = 0;
while (reader.Read())
{
number++;
Console.Write(number);
for (int ii = 0; ii < columns; ii++)
{
string type = reader.GetDataTypeName(ii);
string value = "?";
if (!reader.IsDBNull(ii))
{
if (type.EndsWith("Varchar2"))
{
value = reader.GetString(ii);
}
else if (type.Equals("TimeStamp"))
{
value = reader.GetDateTime(ii).ToString();
}
else if (type.Equals("Int16"))
{
value = reader.GetInt16(ii).ToString();
}
else if (type.Equals("Int32"))
{
value = reader.GetInt32(ii).ToString();
}
}
else
{
value = "(null)";
}
Console.Write(" '{0}'", value);
}
Console.WriteLine();
}
}
Console.WriteLine();
// SELECT WHERE statement
string sql2 = String.Format("select count(*) from {0} where {1}!=:{2}", db_table, db_column, db_column_variable);
Console.WriteLine(sql2);
using (var cmd = new OracleCommand(sql2, conn))
{
OracleParameter par1 = new OracleParameter(db_column_variable, db_column_value);
cmd.Parameters.Add(par1);
Object result = cmd.ExecuteScalar();
Console.WriteLine("Result: {0}", result);
}
Console.WriteLine();
// SELECT package function statement
string sql3 = String.Format("select calculator.factorial(:{0}) from dual", db_factorial_variable);
Console.WriteLine(sql3);
using (var cmd = new OracleCommand(sql3, conn))
{
OracleParameter par1 = new OracleParameter(db_factorial_variable, db_factorial_value);
cmd.Parameters.Add(par1);
Object result = cmd.ExecuteScalar();
Console.WriteLine("Result: {0}", result);
}
Console.WriteLine();
// CALL package procedure statement
string sql4 = String.Format("calculator.add_and_subtract");
Console.WriteLine(sql4);
using (var cmd = new OracleCommand(sql4, conn))
{
cmd.CommandType = CommandType.StoredProcedure;
OracleParameter par1 = new OracleParameter(db_add_and_subtract_a_variable, db_add_and_subtract_a_value);
cmd.Parameters.Add(par1);
OracleParameter par2 = new OracleParameter(db_add_and_subtract_b_variable, db_add_and_subtract_b_value);
cmd.Parameters.Add(par2);
OracleParameter par3 = new OracleParameter(db_add_and_subtract_x_variable, OracleDbType.Int32, ParameterDirection.Output);
cmd.Parameters.Add(par3);
OracleParameter par4 = new OracleParameter(db_add_and_subtract_y_variable, OracleDbType.Int32, ParameterDirection.Output);
cmd.Parameters.Add(par4);
cmd.ExecuteNonQuery();
Console.WriteLine("Result x: {0}", cmd.Parameters[db_add_and_subtract_x_variable].Value);
Console.WriteLine("Result y: {0}", cmd.Parameters[db_add_and_subtract_y_variable].Value);
}
}
}
catch (OracleException oex)
{
Console.WriteLine("Oracle database error: {0}", oex.Message);
}
}
}
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