OracleHelper类

using System;
using System.Configuration;
using System.Data;
using System.Data.OracleClient;
using System.Collections;

namespace PetShop.DBUtility {

    /// 

    /// A helper class used to execute queries against an Oracle database
    /// 
    public abstract class OracleHelper {

        // Read the connection strings from the configuration file
        public static readonly string ConnectionStringLocalTransaction = ConfigurationManager.ConnectionStrings["OraConnString1"].ConnectionString;
        public static readonly string ConnectionStringInventoryDistributedTransaction = ConfigurationManager.ConnectionStrings["OraConnString2"].ConnectionString;
        public static readonly string ConnectionStringOrderDistributedTransaction = ConfigurationManager.ConnectionStrings["OraConnString3"].ConnectionString;
        public static readonly string ConnectionStringProfile = ConfigurationManager.ConnectionStrings["OraProfileConnString"].ConnectionString;
        public static readonly string ConnectionStringMembership = ConfigurationManager.ConnectionStrings["OraMembershipConnString"].ConnectionString;

        //Create a hashtable for the parameter cached
        private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());

        /// 

        /// Execute a database query which does not include a select
        /// 
        /// Connection string to database
        /// Command type either stored procedure or SQL
        /// Acutall SQL Command
        /// Parameters to bind to the command
        /// 
        public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters) {
            // Create a new Oracle command
            OracleCommand cmd = new OracleCommand();

            //Create a connection
            using (OracleConnection connection = new OracleConnection(connectionString)) {

                //Prepare the command
                PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);

                //Execute the command
                int val = cmd.ExecuteNonQuery();
                cmd.Parameters.Clear();
                return val;
            }
        }

        /// 

        /// Execute an OracleCommand (that returns no resultset) against an existing database transaction 
        /// using the provided parameters.
        /// 
        /// 
        /// e.g.:  
        ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders", new OracleParameter(":prodid", 24));
        /// 
        /// an existing database transaction
        /// the CommandType (stored procedure, text, etc.)
        /// the stored procedure name or PL/SQL command
        /// an array of OracleParamters used to execute the command
        /// an int representing the number of rows affected by the command
        public static int ExecuteNonQuery(OracleTransaction trans, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters) {
            OracleCommand cmd = new OracleCommand();
            PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters);
            int val = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            return val;
        }

        /// 

        /// Execute an OracleCommand (that returns no resultset) against an existing database connection 
        /// using the provided parameters.
        /// 
        /// 
        /// e.g.:  
        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new OracleParameter(":prodid", 24));
        /// 
        /// an existing database connection
        /// the CommandType (stored procedure, text, etc.)
        /// the stored procedure name or PL/SQL command
        /// an array of OracleParamters used to execute the command
        /// an int representing the number of rows affected by the command
        public static int ExecuteNonQuery(OracleConnection connection, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters) {

            OracleCommand cmd = new OracleCommand();

            PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
            int val = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            return val;
        }

        /// 

        /// Execute a select query that will return a result set
        /// 
        /// Connection string
        //// the CommandType (stored procedure, text, etc.)
        /// the stored procedure name or PL/SQL command
        /// an array of OracleParamters used to execute the command
        /// 
        public static OracleDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters) {

            //Create the command and connection
            OracleCommand cmd = new OracleCommand();
            OracleConnection conn = new OracleConnection(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
                OracleDataReader 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;
            }
        }

        /// 

        /// Execute an OracleCommand that returns the first column of the first record against the database specified in the connection string 
        /// using the provided parameters.
        /// 
        /// 
        /// e.g.:  
        ///  Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new OracleParameter(":prodid", 24));
        /// 
        /// a valid connection string for a SqlConnection
        /// the CommandType (stored procedure, text, etc.)
        /// the stored procedure name or PL/SQL command
        /// an array of OracleParamters used to execute the command
        /// An object that should be converted to the expected type using Convert.To{Type}
        public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters) {
            OracleCommand cmd = new OracleCommand();

            using (OracleConnection conn = new OracleConnection(connectionString)) {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                object val = cmd.ExecuteScalar();
                cmd.Parameters.Clear();
                return val;
            }
        }

        ///    

        ///    Execute    a OracleCommand (that returns a 1x1 resultset)    against    the    specified SqlTransaction
        ///    using the provided parameters.
        ///    
        ///    A    valid SqlTransaction
        ///    The CommandType (stored procedure, text, etc.)
        ///    The stored procedure name    or PL/SQL command
        ///    An array of    OracleParamters used to execute the command
        ///    An    object containing the value    in the 1x1 resultset generated by the command
        public static object ExecuteScalar(OracleTransaction transaction, CommandType commandType, string commandText, params OracleParameter[] 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
            OracleCommand cmd = new OracleCommand();

            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;
        }

        /// 

        /// Execute an OracleCommand that returns the first column of the first record against an existing database connection 
        /// using the provided parameters.
        /// 
        /// 
        /// e.g.:  
        ///  Object obj = ExecuteScalar(conn, CommandType.StoredProcedure, "PublishOrders", new OracleParameter(":prodid", 24));
        /// 
        /// an existing database connection
        /// the CommandType (stored procedure, text, etc.)
        /// the stored procedure name or PL/SQL command
        /// an array of OracleParamters used to execute the command
        /// An object that should be converted to the expected type using Convert.To{Type}
        public static object ExecuteScalar(OracleConnection connectionString, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters) {
            OracleCommand cmd = new OracleCommand();

            PrepareCommand(cmd, connectionString, null, cmdType, cmdText, commandParameters);
            object val = cmd.ExecuteScalar();
            cmd.Parameters.Clear();
            return val;
        }

        /// 

        /// Add a set of parameters to the cached
        /// 
        /// Key value to look up the parameters
        /// Actual parameters to cached
        public static void CacheParameters(string cacheKey, params OracleParameter[] commandParameters) {
            parmCache[cacheKey] = commandParameters;
        }

        /// 

        /// Fetch parameters from the cache
        /// 
        /// Key to look up the parameters
        /// 
        public static OracleParameter[] GetCachedParameters(string cacheKey) {
            OracleParameter[] cachedParms = (OracleParameter[])parmCache[cacheKey];

            if (cachedParms == null)
                return null;

            // If the parameters are in the cache
            OracleParameter[] clonedParms = new OracleParameter[cachedParms.Length];

            // return a copy of the parameters
            for (int i = 0, j = cachedParms.Length; i < j; i++)
                clonedParms[i] = (OracleParameter)((ICloneable)cachedParms[i]).Clone();

            return clonedParms;
        }

        /// 

        /// Internal function to prepare a command for execution by the database
        /// 
        /// Existing command object
        /// Database connection object
        /// Optional transaction object
        /// Command type, e.g. stored procedure
        /// Command test
        /// Parameters for the command
        private static void PrepareCommand(OracleCommand cmd, OracleConnection conn, OracleTransaction trans, CommandType cmdType, string cmdText, OracleParameter[] 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 (OracleParameter parm in commandParameters)
                    cmd.Parameters.Add(parm);
            }
        }

        /// 

        /// Converter to use boolean data type with Oracle
        /// 
        /// Value to convert
        /// 
        public static string OraBit(bool value) {
            if(value)
                return "Y";
            else
                return "N";
        }

        /// 

        /// Converter to use boolean data type with Oracle
        /// 
        /// Value to convert
        /// 
        public static bool OraBool(string value) {
            if(value.Equals("Y"))
                return true;
            else
                return false;
        } 
    }
}

 

转载于:https://www.cnblogs.com/EleMMent/p/3140448.html