using System;
using System.Configuration;
using System.Data;
using System.Data.OracleClient;
using System.Collections;
using System.Data.OleDb;
namespace DBUtility
{
/// <summary>
/// A helper class used to execute queries against an Oracle database
/// </summary>
public abstract class OracleHelper
{
// Read the connection strings from the configuration file
public static readonly string connectionString = ConfigurationManager.AppSettings["OrdersDAL"];
//Create a hashtable for the parameter cached
private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());
/// <summary>
/// Execute a database query which does not include a select
/// </summary>
/// <param name="connString">Connection string to database</param>
/// <param name="cmdType">Command type either stored procedure or SQL</param>
/// <param name="cmdText">Acutall SQL Command</param>
/// <param name="commandParameters">Parameters to bind to the command</param>
/// <returns></returns>
public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params OleDbParameter[] commandParameters)
{
// Create a new Oracle command
OleDbCommand cmd = new OleDbCommand();
//Create a connection
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
//Prepare the command
PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
//Execute the command
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}
}
/// <summary>
/// Execute an OleDbCommand (that returns no resultset) against an existing database transaction
/// using the provided parameters.
/// </summary>
/// <remarks>
/// e.g.:
/// int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders", new OleDbParameter(":prodid", 24));
/// </remarks>
/// <param name="trans">an existing database transaction</param>
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">the stored procedure name or PL/SQL command</param>
/// <param name="commandParameters">an array of OracleParamters used to execute the command</param>
/// <returns>an int representing the number of rows affected by the command</returns>
public static int ExecuteNonQuery(OleDbTransaction trans, CommandType cmdType, string cmdText, params OleDbParameter[] commandParameters)
{
OleDbCommand cmd = new OleDbCommand();
PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}
/// <summary>
/// Execute an OleDbCommand (that returns no resultset) against an existing database connection
/// using the provided parameters.
/// </summary>
/// <remarks>
/// e.g.:
/// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new OleDbParameter(":prodid", 24));
/// </remarks>
/// <param name="conn">an existing database connection</param>
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">the stored procedure name or PL/SQL command</param>
/// <param name="commandParameters">an array of OracleParamters used to execute the command</param>
/// <returns>an int representing the number of rows affected by the command</returns>
public static int ExecuteNonQuery(OleDbConnection connection, CommandType cmdType, string cmdText, params OleDbParameter[] commandParameters)
{
OleDbCommand cmd = new OleDbCommand();
PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}
/// <summary>
/// Execute a select query that will return a result set
/// </summary>
/// <param name="connString">Connection string</param>
//// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">the stored procedure name or PL/SQL command</param>
/// <param name="commandParameters">an array of OracleParamters used to execute the command</param>
/// <returns></returns>
public static OleDbDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params OleDbParameter[] commandParameters)
{
//Create the command and connection
OleDbCommand cmd = new OleDbCommand();
OleDbConnection conn = new OleDbConnection(connectionString);
try
{
//Prepare the command to execute
PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
//Execute the query, stating that the connection should close when the resulting datareader has been read
OleDbDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
cmd.Parameters.Clear();
return rdr;
}
catch
{
//If an error occurs close the connection as the reader will not be used and we expect it to close the connection
conn.Close();
throw;
}
}
/// <summary>
/// Execute an OleDbCommand that returns the first column of the first record against the database specified in the connection string
/// using the provided parameters.
/// </summary>
/// <remarks>
/// e.g.:
/// Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new OleDbParameter(":prodid", 24));
/// </remarks>
/// <param name="connectionString">a valid connection string for a SqlConnection</param>
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">the stored procedure name or PL/SQL command</param>
/// <param name="commandParameters">an array of OracleParamters used to execute the command</param>
/// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, params OleDbParameter[] commandParameters)
{
OleDbCommand cmd = new OleDbCommand();
using (OleDbConnection conn = new OleDbConnection(connectionString))
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
object val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return val;
}
}
/// <summary>
/// Execute a OleDbCommand (that returns a 1x1 resultset) against the specified SqlTransaction
/// using the provided parameters.
/// </summary>
/// <param name="transaction">A valid SqlTransaction</param>
/// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">The stored procedure name or PL/SQL command</param>
/// <param name="commandParameters">An array of OracleParamters used to execute the command</param>
/// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
public static object ExecuteScalar(OleDbTransaction transaction, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
{
if (transaction == null)
throw new ArgumentNullException("transaction");
if (transaction != null && transaction.Connection == null)
throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
// Create a command and prepare it for execution
OleDbCommand cmd = new OleDbCommand();
PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters);
// Execute the command & return the results
object retval = cmd.ExecuteScalar();
// Detach the SqlParameters from the command object, so they can be used again
cmd.Parameters.Clear();
return retval;
}
/// <summary>
/// Execute an OleDbCommand that returns the first column of the first record against an existing database connection
/// using the provided parameters.
/// </summary>
/// <remarks>
/// e.g.:
/// Object obj = ExecuteScalar(conn, CommandType.StoredProcedure, "PublishOrders", new OleDbParameter(":prodid", 24));
/// </remarks>
/// <param name="conn">an existing database connection</param>
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">the stored procedure name or PL/SQL command</param>
/// <param name="commandParameters">an array of OracleParamters used to execute the command</param>
/// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
public static object ExecuteScalar(OleDbConnection connectionString, CommandType cmdType, string cmdText, params OleDbParameter[] commandParameters)
{
OleDbCommand cmd = new OleDbCommand();
PrepareCommand(cmd, connectionString, null, cmdType, cmdText, commandParameters);
object val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return val;
}
/// <summary>
/// Add a set of parameters to the cached
/// </summary>
/// <param name="cacheKey">Key value to look up the parameters</param>
/// <param name="commandParameters">Actual parameters to cached</param>
public static void CacheParameters(string cacheKey, params OleDbParameter[] commandParameters)
{
parmCache[cacheKey] = commandParameters;
}
/// <summary>
/// Fetch parameters from the cache
/// </summary>
/// <param name="cacheKey">Key to look up the parameters</param>
/// <returns></returns>
public static OleDbParameter [] GetCachedParameters(string cacheKey)
{
OleDbParameter[] cachedParms = (OleDbParameter[])parmCache[cacheKey];
if (cachedParms == null)
return null;
// If the parameters are in the cache
OleDbParameter[] clonedParms = new OleDbParameter[cachedParms.Length];
// return a copy of the parameters
for (int i = 0, j = cachedParms.Length; i < j; i++)
clonedParms[i] = (OleDbParameter)((ICloneable)cachedParms[i]).Clone();
return clonedParms;
}
/// <summary>
/// Internal function to prepare a command for execution by the database
/// </summary>
/// <param name="cmd">Existing command object</param>
/// <param name="conn">Database connection object</param>
/// <param name="trans">Optional transaction object</param>
/// <param name="cmdType">Command type, e.g. stored procedure</param>
/// <param name="cmdText">Command test</param>
/// <param name="commandParameters">Parameters for the command</param>
private static void PrepareCommand(OleDbCommand cmd, OleDbConnection conn, OleDbTransaction trans, CommandType cmdType, string cmdText, OleDbParameter[] commandParameters)
{
//Open the connection if required
if (conn.State != ConnectionState.Open)
conn.Open();
//Set up the command
cmd.Connection = conn;
cmd.CommandText = cmdText;
cmd.CommandType = cmdType;
//Bind it to the transaction if it exists
if (trans != null)
cmd.Transaction = trans;
// Bind the parameters passed in
if (commandParameters != null)
{
foreach (OleDbParameter parm in commandParameters)
cmd.Parameters.Add(parm);
}
}
/// <summary>
/// Converter to use boolean data type with Oracle
/// </summary>
/// <param name="value">Value to convert</param>
/// <returns></returns>
public static string OraBit(bool value)
{
if (value)
return "Y";
else
return "N";
}
/// <summary>
/// Converter to use boolean data type with Oracle
/// </summary>
/// <param name="value">Value to convert</param>
/// <returns></returns>
public static bool OraBool(string value)
{
if (value.Equals("Y"))
return true;
else
return false;
}
}
}
