//===============================================================================
// This file is based on the Microsoft Data Access Application Block for .NET
// For more information please go to 
// http://msdn.microsoft.com/library/en-us/dnbda/html/daab-rm.asp
//===============================================================================

using System;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Collections;

namespace Mammonth.Common
{

    /// <summary>
    /// The SqlHelper class is intended to encapsulate high performance, 
    /// scalable best practices for common uses of SqlClient.
    /// </summary>
    public abstract class SqlHelper
    {

        ////Database connection strings
        //public static readonly string ConnectionStringLocalTransaction =  ConfigurationManager.AppSettings["SQLConnString1"];
        //public static readonly string ConnectionStringInventoryDistributedTransaction =  ConfigurationManager.AppSettings["SQLConnString2"];
        //public static readonly string ConnectionStringOrderDistributedTransaction =  ConfigurationManager.AppSettings["SQLConnString3"];
        //public static readonly string ConnectionStringProfile =  ConfigurationManager.AppSettings["SQLProfileConnString"];
        public static readonly string ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

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

        /// <summary>
        /// Execute a SqlCommand (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 SqlParameter("@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 T-SQL command</param>
        /// <param name="commandParameters">an array of SqlParamters 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, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {

            SqlCommand cmd = new SqlCommand();

            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                int val = cmd.ExecuteNonQuery();
                cmd.Parameters.Clear();
                return val;
            }
        }

        /// <summary>
        /// Execute a SqlCommand (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 SqlParameter("@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 T-SQL command</param>
        /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
        /// <returns>an int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {

            SqlCommand cmd = new SqlCommand();

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

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

        /// <summary>
        /// Execute a SqlCommand that returns a resultset against the database specified in the connection string 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  SqlDataReader r = ExecuteReader(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@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 T-SQL command</param>
        /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
        /// <returns>A SqlDataReader containing the results</returns>
        public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            SqlConnection conn = new SqlConnection(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, commandParameters);
                SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
               // cmd.Parameters.Clear();
                return rdr;
            }
            catch
            {
                conn.Close();
                throw;
            }
        }



        /// <summary>
        /// Execute a SqlCommand 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 SqlParameter("@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 T-SQL command</param>
        /// <param name="commandParameters">an array of SqlParamters 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 SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();

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

        /// <summary>
        /// Execute a SqlCommand 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(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@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 T-SQL command</param>
        /// <param name="commandParameters">an array of SqlParamters 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(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {

            SqlCommand cmd = new SqlCommand();

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

        /// <summary>
        /// add parameter array to the cache
        /// </summary>
        /// <param name="cacheKey">Key to the parameter cache</param>
        /// <param name="cmdParms">an array of SqlParamters to be cached</param>
        public static void CacheParameters(string cacheKey, params SqlParameter[] commandParameters)
        {
            parmCache[cacheKey] = commandParameters;
        }

        /// <summary>
        /// Retrieve cached parameters
        /// </summary>
        /// <param name="cacheKey">key used to lookup parameters</param>
        /// <returns>Cached SqlParamters array</returns>
        public static SqlParameter[] GetCachedParameters(string cacheKey)
        {
            SqlParameter[] cachedParms = (SqlParameter[])parmCache[cacheKey];

            if (cachedParms == null)
                return null;

            SqlParameter[] clonedParms = new SqlParameter[cachedParms.Length];

            for (int i = 0, j = cachedParms.Length; i < j; i++)
                clonedParms[i] = (SqlParameter)((ICloneable)cachedParms[i]).Clone();

            return clonedParms;
        }

        /// <summary>
        /// Prepare a command for execution
        /// </summary>
        /// <param name="cmd">SqlCommand object</param>
        /// <param name="conn">SqlConnection object</param>
        /// <param name="trans">SqlTransaction 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">SqlParameters to use in the command</param>
        private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] 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 (SqlParameter parm in cmdParms)
                    cmd.Parameters.Add(parm);
            }
        }

        #region 创建参数 ---2013-05-14 By:yangguoji
        /// <summary>
        /// 定义参数
        /// </summary>
        /// <param name="ParameterName">参数名字</param>
        /// <param name="DbType">参数类型</param>
        /// <param name="Size">参数大小</param>
        /// <param name="Direction">指向</param>
        /// <param name="Value">值</param>
        /// <returns>SqlParameter</returns>
        public static SqlParameter CreateParameter(string ParameterName, SqlDbType DbType, int Size, ParameterDirection Direction, object Value)
        {
            //定义参数实例
            SqlParameter parameter;

            //判断是：eg:varchar(20)
            //如果是字符串类型的就要在后面定义size
            if (Size > 0)
            {
                //构造函数
                parameter = new SqlParameter(ParameterName, DbType, Size);
            }
            //eg:int
            //如果是整型就不需要在后面加上size
            else
            {
                //构造函数
                parameter = new SqlParameter(ParameterName, DbType);
            }
            //指向
            parameter.Direction = Direction;
            //input
            if ((Direction != ParameterDirection.Output) || (Value != null))
            {
                parameter.Value = Value;
            }
            //返回参数实例
            return parameter;
        }

        /// <summary>
        /// 定义输入参数
        /// </summary>
        /// <param name="ParameterName">参数名字</param>
        /// <param name="DbType">参数类型</param>
        /// <param name="Size">参数大小</param>
        /// <param name="Value">值</param>
        /// <returns>SqlParameter</returns>
        public static SqlParameter CreateInputParameter(string ParameterName, SqlDbType DbType, int Size, object Value)
        {
            return CreateParameter(ParameterName, DbType, Size, ParameterDirection.Input, Value);
        }

        /// <summary>
        /// 定义输入参数
        /// </summary>
        /// <param name="ParameterName">参数名字</param>
        /// <param name="DbType">参数类型</param>
        /// <param name="Value">值</param>
        /// <returns>SqlParameter</returns>
        public static SqlParameter CreateInputParameter(string ParameterName, SqlDbType DbType, object Value)
        {
            return CreateParameter(ParameterName, DbType, 0, ParameterDirection.Input, Value);
        }

        /// <summary>
        /// 定义输出参数
        /// </summary>
        /// <param name="ParameterName">参数名字</param>
        /// <param name="DbType">参数类型</param>
        /// <param name="Size">参数大小</param>
        /// <returns>SqlParameter</returns>
        public static SqlParameter CreateOutputParameter(string ParameterName, SqlDbType DbType, int Size)
        {
            return CreateParameter(ParameterName, DbType, Size, ParameterDirection.Output, null);
        }

        /// <summary>
        /// 定义输出参数
        /// </summary>
        /// <param name="ParameterName">参数名字</param>
        /// <param name="DbType">参数类型</param>
        /// <returns>SqlParameter</returns>
        public static SqlParameter CreateOutputParameter(string ParameterName, SqlDbType DbType)
        {
            return CreateParameter(ParameterName, DbType, 0, ParameterDirection.Output, null);
        }

        /// <summary>
        /// 返回值
        /// </summary>
        /// <param name="ParameterName">参数名字</param>
        /// <param name="DbType">参数类型</param>
        /// <param name="Size">参数大小</param>
        /// <returns>SqlParameter</returns>
        public static SqlParameter CreateReturnParameter(string ParameterName, SqlDbType DbType, int Size)
        {
            //这个指向既不是输入也不是输出，而是返回值
            return CreateParameter(ParameterName, DbType, Size, ParameterDirection.ReturnValue, null);
        }

        /// <summary>
        /// 返回值
        /// </summary>
        /// <param name="ParameterName">参数名字</param>
        /// <param name="DbType">参数类型</param>
        /// <returns>SqlParameter</returns>
        public static SqlParameter CreateReturnParameter(string ParameterName, SqlDbType DbType)
        {
            //这个指向既不是输入也不是输出，而是返回值
            return CreateParameter(ParameterName, DbType, 0, ParameterDirection.ReturnValue, null);
        }
        #endregion

        #region 返回DataSet、Datatable  ---2013-05-14 By:yangguoji
        /// <summary>
        /// 执行Sql命令，返回DataSet结果集
        /// </summary>
        /// <param name="connectionString">连接字符串</param>
        /// <param name="cmdType">执行命令类型</param>
        /// <param name="cmdText">执行的命令</param>
        /// <param name="commandParameters">参数</param>
        /// <returns>DataSet</returns>
        public static DataSet ExecuteDataSet(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                SqlDataAdapter dataadapter = new SqlDataAdapter(cmd);
                DataSet dataset = new DataSet();
                dataadapter.Fill(dataset);
                cmd.Parameters.Clear();
                return dataset;
            }
        }

        /// <summary>
        /// 执行Sql命令，返回DataSet结果集
        /// </summary>
        /// <param name="conn">一个已经存在的数据库连接</param>
        /// <param name="cmdType">执行命令类型</param>
        /// <param name="cmdText">执行的命令</param>
        /// <param name="commandParameters">参数</param>
        /// <returns>DataSet</returns>
        public static DataSet ExecuteDataSet(SqlConnection conn, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
            SqlDataAdapter dataadapter = new SqlDataAdapter(cmd);
            DataSet dataset = new DataSet();
            dataadapter.Fill(dataset);
            cmd.Parameters.Clear();
            return dataset;

        }

        /// <summary>
        /// 执行Sql命令，返回DataTable结果集
        /// </summary>
        /// <param name="connectionString">连接字符串</param>
        /// <param name="cmdType">执行命令类型</param>
        /// <param name="cmdText">执行的命令</param>
        /// <param name="commandParameters">参数</param>
        /// <returns>DataTable</returns>
        public static DataTable ExecuteDataTable(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                SqlDataAdapter dataadapter = new SqlDataAdapter(cmd);
                DataTable datatable = new DataTable();
                dataadapter.Fill(datatable);
                cmd.Parameters.Clear();
                return datatable;
            }
        }

        /// <summary>
        /// 执行Sql命令，返回DataTable结果集
        /// </summary>
        /// <param name="conn">一个已经存在的数据库连接</param>
        /// <param name="cmdType">执行命令类型</param>
        /// <param name="cmdText">执行的命令</param>
        /// <param name="commandParameters">参数</param>
        /// <returns>DataTable</returns>
        public static DataTable ExecuteDataTable(SqlConnection conn, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
            SqlDataAdapter dataadapter = new SqlDataAdapter(cmd);
            DataTable datatable = new DataTable();
            dataadapter.Fill(datatable);
            cmd.Parameters.Clear();
            return datatable;

        }
        #endregion
    }
}