修改的某人的SqlHelper FOR ODBC

随便找来的,源作者不明.

本来是SQL SERVER 的 修改为 ODBC使用.

并且修改了连接字符串,可以允许修改一次.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;
using System.Collections;
using System.Data;

using System.Data.Odbc;

namespace DBUtility
{
    public abstract class OdbcHelper
    {
        //Database connection strings
        private static string connectionStringDefault;

	    public static string ConnectionStringDefault
	    {
		    get {
                if(string.IsNullOrEmpty(connectionStringDefault))
                {
                    return  connectionStringDefault = ConfigurationManager.ConnectionStrings["OdbcConnStringDefault"].ConnectionString;
                }
                else
                {
                    return connectionStringDefault;
                }
            }
		    set {
                if (string.IsNullOrEmpty(connectionStringDefault))
                    connectionStringDefault = value;
            }
	    }

        //Hashtable to store cached parameters
        private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());

        /// <summary>
        /// add parameter array to the cache
        /// </summary>
        /// <param name="cacheKey">Key to the parameter cache</param>
        /// <param name="cmdParameters">an array of OdbcParamters to be cached</param>
        public static void SetCacheParameters(string cacheKey, params OdbcParameter[] parameters)
        {

            parmCache[cacheKey] = parameters;
        }

        /// <summary>
        /// Retrieve cached parameters
        /// </summary>
        /// <param name="cacheKey">key used to lookup parameters</param>
        /// <returns>Cached OdbcParamters array</returns>
        public static OdbcParameter[] GetCacheParameters(string cacheKey)
        {
            OdbcParameter[] cachedParms = (OdbcParameter[])parmCache[cacheKey];
            if (cachedParms == null)
            {
                return null;
            }
            OdbcParameter[] clonedParms = new OdbcParameter[cachedParms.Length];
            for (int i = 0; i < cachedParms.Length; i++)
            {
                clonedParms[i] = (OdbcParameter)((ICloneable)cachedParms[i]).Clone();
            }
            return clonedParms;
        }

        /// <summary>
        /// Prepare a command for execution
        /// </summary>
        /// <param name="cmd">OdbcCommand object</param>
        /// <param name="conn">OdbcConneciotn object</param>
        /// <param name="trans">OdbcTransaction object</param>
        /// <param name="cmdType">Cmd type e.g. stored procedure or text</param>
        /// <param name="cmdText">Command text, e.g. Select * From Products</param>
        /// <param name="cmdParms">OdbcParameters to use in the command</param>
        private static void PrepareCommand(OdbcCommand cmd, OdbcConnection conn, OdbcTransaction trans, CommandType cmdType, string cmdText, OdbcParameter[] cmdParms)
        {
            if (conn.State != ConnectionState.Open)
            {
                conn.Open();
            }
            cmd.Connection = conn;
            cmd.CommandText = cmdText;
            if (trans != null)
            {
                cmd.Transaction = trans;
            }
            cmd.CommandType = cmdType;
            if (cmdParms != null)
            {
                foreach (OdbcParameter parm in cmdParms)
                {
                    cmd.Parameters.Add(parm);
                }
            }
        }

        /// <summary>
        /// Execute a OdbcCommand (that returns no resultset) against the database specified in the connection string using the provided parameters.
        /// </summary>
        /// <param name="connectionString">a valid conneciotn string for a OdbcConnection</param>
        /// <param name="cmdText">the stored procedure name or T-Odbc command</param>
        /// <returns>an int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(string connectionString, string cmdText)
        {
            if (connectionString == null)
            {
                connectionString = ConnectionStringDefault;
            }
            return ExecuteNonQuery(connectionString, cmdText, CommandType.Text, null);
        }

        /// <summary>
        /// Execute a OdbcCommand (that returns no resultset) against the database specified in the connection string using the provided parameters.
        /// </summary>
        /// <param name="connectionString">a valid conneciotn string for a OdbcConnection</param>
        /// <param name="cmdType">the CommandType (stored procedure,text,etc.)</param>
        /// <param name="cmdText">the stored procedure name or T-Odbc command</param>
        /// <returns>an int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(string connectionString, string cmdText, CommandType cmdType)
        {
            if (connectionString == null)
            {
                connectionString = ConnectionStringDefault;
            }
            return ExecuteNonQuery(connectionString, cmdText, cmdType, null);
        }

        /// <summary>
        /// Execute a OdbcCommand (that returns no resultset) against the database specified in the connection string using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:
        /// int result=ExecuteNonQuery(connString,CommandType.StoredProcedure,"PublishOrders",new OdbcParameter("@prodid",24));
        /// </remarks>
        /// <param name="connectionString">a valid conneciotn string for a OdbcConnection</param>
        /// <param name="cmdType">the CommandType (stored procedure,text,etc.)</param>
        /// <param name="cmdText">the stored procedure name or T-Odbc command</param>
        /// <param name="commandParameters">an array of OdbcParameters used to execute the command</param>
        /// <returns>an int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(string connectionString, string cmdText, CommandType cmdType, params OdbcParameter[] commandParameters)
        {
            if (connectionString == null)
            {
                connectionString = ConnectionStringDefault;
            }
            OdbcCommand cmd = new OdbcCommand();
            using (OdbcConnection conn = new OdbcConnection(connectionString))
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                int val = cmd.ExecuteNonQuery();
                cmd.Parameters.Clear();
                return val;
            }
        }

        /// <summary>
        /// Execute a OdbcCommand (that returns no resultset) using an existing Odbc Transaction using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:
        ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders", new OdbcParameter("@prodid", 24));
        /// </remarks>
        /// <param name="trans">an existing Odbc transaction</param>
        /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">the stored procedure name or T-Odbc command</param>
        /// <param name="commandParameters">an array of OdbcParamters used to execute the command</param>
        /// <returns>an int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(OdbcTransaction trans, string cmdText, CommandType cmdType, params OdbcParameter[] commandParameters)
        {
            int val = 0;
            using (OdbcCommand cmd = new OdbcCommand())
            {
                PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters);
                val = cmd.ExecuteNonQuery();
                cmd.Parameters.Clear();
            }
            return val;
        }

        /// <summary>
        /// Execute a OdbcCommand that returns a resultset against the database specified in the connection string using the provided parameters
        /// </summary>
        /// <param name="connectionString">a valid connection string for a OdbcConnection</param>
        /// <param name="cmdType">the CommandType(stored procedure,text,etc.)</param>
        /// <param name="cmdText">the stroed procedure name or T-Odbc command</param>
        /// <param name="cmdParameters">an array of OdbcParameters used to execute the command</param>
        /// <returns>A OdbcDataReader containing the results</returns>
        public static OdbcDataReader ExecuteReader(string connectionString, string cmdText, CommandType cmdType, params OdbcParameter[] cmdParameters)
        {
            if (connectionString == null)
            {
                connectionString = ConnectionStringDefault;
            }
            OdbcCommand cmd = new OdbcCommand();
            OdbcConnection conn = new OdbcConnection(connectionString);
            // we use a try/catch here because if the method throws an exception we want to
            // close the connection throw code, because no datareader will exist, hence the
            // commandBehaviour.CloseConnection will not work
            try
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, cmdParameters);
                OdbcDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                cmd.Parameters.Clear();
                return dr;
            }
            catch (Exception)
            {
                conn.Close();
                throw;
            }
        }

        /// <summary>
        /// Execute a OdbcCommand that return a resultset against the database specified in the connection string using the provided parameters
        /// </summary>
        /// <param name="connectionString">a valid connection string for a OdbcConnection</param>
        /// <param name="cmdType">the CommandType(stored procedure,text,etc.)</param>
        /// <param name="cmdText">the stored procedure name or T-Odbc command</param>
        /// <param name="cmdParameters">an array of OdbcParameters userd to execute the command</param>
        /// <returns>A DataTable containing the results</returns>
        public static DataTable ExecuteDataTable(string connectionString, string cmdText, CommandType cmdType, params OdbcParameter[] cmdParameters)
        {
            if (connectionString == null)
            {
                connectionString = ConnectionStringDefault;
            }
            DataTable dt = new DataTable();
            using (OdbcConnection conn = new OdbcConnection(connectionString))
            {
                using (OdbcCommand cmd = new OdbcCommand())
                {
                    PrepareCommand(cmd, conn, null, cmdType, cmdText, cmdParameters);
                    OdbcDataAdapter adapter = new OdbcDataAdapter(cmd);
                    adapter.Fill(dt);
                }
            }
            return dt;
        }

        /// <summary>
        /// Execute a OdbcCommand 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 OdbcParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connectionString">a valid connection string for a OdbcConnection</param>
        /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">the stored procedure name or T-Odbc command</param>
        /// <param name="commandParameters">an array of OdbcParameters 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, string cmdText, CommandType cmdType, params OdbcParameter[] commandParameters)
        {
            if (connectionString == null)
            {
                connectionString = ConnectionStringDefault;
            }
            object val = null;
            using (OdbcConnection connection = new OdbcConnection(connectionString))
            {
                using (OdbcCommand cmd = new OdbcCommand())
                {
                    PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
                    val = cmd.ExecuteScalar();
                    cmd.Parameters.Clear();
                }
                return val;
            }
        }

    }
}

使用方式:

string conString = "Driver={SQL Native Client};Server=abc;Database=Items;Uid=sa;Pwd=111111;";

            DBUtility.OdbcHelper.ConnectionStringDefault = conString;
            DataTable dt = DBUtility.OdbcHelper.ExecuteDataTable(conString, "SELECT * FROM item", CommandType.Text, null);