連接任何數據庫的類(一)

using System;
using System.Data;
using System.Data.Odbc;
using System.Data.OleDb;
using System.Data.SqlClient;
using System.Data.Common;

namespace DBSpaceName
{

    public class DataFactory
    {
        public DataFactory(){}

        /**//// <summary>
        /// 創建一個IDbConnection對象
        /// </summary>
        /// <param name="connectionString">ConnectionString值</param>
        /// <param name="dbType">數據庫類型</param>
        /// <returns>IDbConnection對象</returns>
        public static IDbConnection CreateConnection(string connectionString, DataBaseType dbType)
        {
            IDbConnection cnn;
            switch(dbType)
            {
                case DataBaseType.Access:
                    cnn = new OleDbConnection(connectionString);
                    break;
                case DataBaseType.Sql:
                    cnn = new SqlConnection(connectionString);
                    break;
                default:
                    cnn = new SqlConnection(connectionString);
                    break;
            }
            return cnn;
        }

        /**//// <summary>
        /// 創建一個IDbCommand對象
        /// </summary>
        /// <param name="commandText">CommandText值</param>
        /// <param name="dbType">數據庫類型</param>
        /// <param name="cnn">IDbConnection對象</param>
        /// <returns>IDbCommand對象</returns>
        public static IDbCommand CreateCommand(string commandText, DataBaseType dbType, IDbConnection cnn)
        {
            IDbCommand cmd;
            switch(dbType)
            {
                case DataBaseType.Access:
                    cmd = new OleDbCommand(commandText,(OleDbConnection)cnn);
                    break;
                case DataBaseType.Sql:
                    cmd = new SqlCommand(commandText,(SqlConnection)cnn);
                    break;
                default:
                    cmd = new SqlCommand(commandText,(SqlConnection)cnn);
                    break;
            }
            return cmd;
        }

        /**//// <summary>
        /// 創建一個IDbCommand對象
        /// </summary>
        /// <param name="dbType">數據庫類型</param>
        /// <param name="cnn">IDbConnection對象</param>
        /// <returns>IDbCommand對象</returns>
        public static IDbCommand CreateCommand(DataBaseType dbType, IDbConnection cnn)
        {
            IDbCommand cmd;
            switch(dbType)
            {
                case DataBaseType.Access:
                    cmd = new OleDbCommand();
                    cmd.Connection = (OleDbConnection)cnn;
                    break;
                case DataBaseType.Sql:
                    cmd = new SqlCommand();
                    cmd.Connection = (SqlConnection)cnn;
                    break;
                default:
                    cmd = new SqlCommand();
                    cmd.Connection = (SqlConnection)cnn;
                    break;
            }
            return cmd;
        }

        /**//// <summary>
        /// 給Command中的存儲過存或Sql語句中的參數賦值
        /// </summary>
        /// <param name="cmd">IDbCommand對象</param>
        /// <param name="parameters">參數數組</param>
        /// <returns>已經賦值的IDbCommand對象</returns>
        public static IDbCommand CreateCommand(IDbCommand cmd, IDataParameter[] parameters)
        {
            foreach(IDataParameter parameter in parameters)
            {
                if(parameter != null)
                {
                    if((parameter.Direction==ParameterDirection.InputOutput || parameter.Direction==ParameterDirection.Input)
                        && (parameter.Value==null))
                    {
                        parameter.Value = DBNull.Value;
                    }
                    cmd.Parameters.Add(parameter);
                }
            }
            return cmd;
        }
        /**//// <summary>
        /// 給Command中的存儲過存或Sql語句中的參數賦值
        /// </summary>
        /// <param name="cmd">IDbCommand</param>
        /// <param name="parameter">參數</param>
        /// <returns>已經賦值的IDbCommand對象</returns>
        public static IDbCommand CreateCommand(IDbCommand cmd, IDataParameter parameter)
        {
            if(parameter != null)
            {
                if((parameter.Direction==ParameterDirection.InputOutput || parameter.Direction==ParameterDirection.Input)
                    && (parameter.Value==null))
                {
                    parameter.Value = DBNull.Value;
                }
                cmd.Parameters.Add(parameter);
            }
            return cmd;
        }

        /**//// <summary>
        /// 建立一個IDataParameter參數
        /// </summary>
        /// <param name="parameterName">參數名</param>
        /// <param name="parameterValue">參數值</param>
        /// <param name="dbType">數據庫類型</param>
        /// <returns>IDataParameter對象</returns>
        public static IDataParameter CreateParameter(string parameterName, object parameterValue,ParameterDirection direction,DataBaseType dbType)
        {
            IDataParameter parameter;
            switch(dbType)
            {
                case DataBaseType.Access:
                    parameter = new OleDbParameter("@"+parameterName,parameterValue);
                    break;
                case DataBaseType.Sql:
                    parameter = new SqlParameter("@"+parameterName,parameterValue);
                    break;
                default:
                    parameter = new SqlParameter("@"+parameterName,parameterValue);
                    break;
            }
            parameter.Direction = direction;
            return parameter;
        }

        /**//// <summary>
        /// 創建一個DbDataAdapter對象
        /// </summary>
        /// <param name="cmd">IDbCommand對象</param>
        /// <param name="dbType">數據庫類型</param>
        /// <returns>DbDataAdapter對象</returns>
        /// 
        public static DbDataAdapter CreateAdapter(IDbCommand cmd, DataBaseType dbType)
        {
            DbDataAdapter da;
            switch(dbType)
            {
                case DataBaseType.Access:
                    da = new OleDbDataAdapter((OleDbCommand)cmd);
                    break;
                case DataBaseType.Sql:
                    da = new SqlDataAdapter((SqlCommand)cmd);
                    break;
                default:
                    da = new SqlDataAdapter((SqlCommand)cmd);
                    break;
            }
            return da;
        }


    }
}