using System;
using System.Collections;
using System.Collections.Specialized;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using System.Configuration;
using System.Web;
/// <summary>
///DbHelp 的摘要说明
/// </summary>
public abstract class DbHelp
{

//数据库连接字符串(web.config来配置)，可以动态更改connectionString支持多数据库.		
 public static string connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

	public DbHelp(){}

 /// <summary>
        /// 取得最大记录
        /// </summary>
        /// <param name="FieldName"></param>
        /// <param name="TableName"></param>
        /// <returns></returns>
        public static int GetMaxID(string FieldName, string TableName)
        {
            string strsql = "select top 1 " + FieldName + " from " + TableName + " order by " + FieldName + " desc";
            object obj = GetSingle(strsql);
            if (obj == null)
            {
                return 0;
            }
            else
            {
                return int.Parse(obj.ToString());
            }
        }

        /// <summary>
        /// 查询该记录是否存在 简单
        /// </summary>
        /// <param name="strSql"></param>
        /// <returns></returns>
        public static bool Exists(string strSql)
        {
            object obj = GetSingle(strSql);
            int cmdresult;
            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
            {
                cmdresult = 0;
            }
            else
            {
                cmdresult = int.Parse(obj.ToString());
            }
            if (cmdresult == 0)
            {
                return false;
            }
            else
            {
                return true;
            }
        }
        /// <summary>
        /// 查询该记录是否存在 参数化
        /// </summary>
        /// <param name="strSql"></param>
        /// <param name="cmdParms"></param>
        /// <returns></returns>
        public static bool Exists(string strSql, params SqlParameter[] cmdParms)
        {
            object obj = GetSingle(strSql, cmdParms);
            int cmdresult;
            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
            {
                cmdresult = 0;
            }
            else
            {
                cmdresult = int.Parse(obj.ToString());
            }
            if (cmdresult == 0)
            {
                return false;
            }
            else
            {
                return true;
            }
        }

        /// <summary>
        /// 执行SQL语句，返回影响的记录数
        /// </summary>
        /// <param name="SQLString">SQL语句</param>
        /// <returns>影响的记录数</returns>
        public static int ExecuteSql(string SQLString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                using (SqlCommand cmd = new SqlCommand(SQLString, connection))
                {
                    try
                    {
                        connection.Open();
                        int rows = cmd.ExecuteNonQuery();
                        return rows;
                    }
                    catch (System.Data.SqlClient.SqlException E)
                    {
                        connection.Close();
                        throw new Exception(E.Message);
                    }
                }
            }
        }


        /// <summary>
        /// 执行SQL语句，返回DataTable
        /// </summary>
        /// <param name="SQLString">SQL语句</param>
        /// <returns>DataTable</returns>
        public static DataTable DataTableSql(string SQLString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                using (SqlDataAdapter dar = new SqlDataAdapter(SQLString, connection))
                {
                    try
                    {
                        connection.Open();
                        DataSet table = new DataSet();
                        dar.Fill(table);
                        return table.Tables[0] ;
                    }
                    catch (System.Data.SqlClient.SqlException E)
                    {
                        connection.Close();
                        throw new Exception(E.Message);
                    }
                }
            }
        }
        /// <summary>
        /// 2012-2-20日新增重载，执行SQL语句，返回影响的记录数
        /// </summary>
        /// <param name="connection">SqlConnection对象</param>
        /// <param name="trans">SqlTransaction对象</param>
        /// <param name="SQLString">SQL语句</param>
        /// <returns>影响的记录数</returns>
        public static int ExecuteSql(SqlConnection connection, SqlTransaction trans, string SQLString)
        {
            using (SqlCommand cmd = new SqlCommand(SQLString, connection))
            {
                try
                {
                    cmd.Connection = connection;
                    cmd.Transaction = trans;
                    int rows = cmd.ExecuteNonQuery();
                    return rows;
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    trans.Rollback();
                    throw new Exception(E.Message);
                }
            }
        }

        /// <summary>
        /// 执行多条SQL语句，实现数据库事务。
        /// </summary>
        /// <param name="SQLStringList">多条SQL语句</param>		
        public static bool ExecuteSqlTran(ArrayList SQLStringList)
        {
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                conn.Open();
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = conn;
                SqlTransaction tx = conn.BeginTransaction();
                cmd.Transaction = tx;
                try
                {
                    for (int n = 0; n < SQLStringList.Count; n++)
                    {
                        string strsql = SQLStringList[n].ToString();
                        if (strsql.Trim().Length > 1)
                        {
                            cmd.CommandText = strsql;
                            cmd.ExecuteNonQuery();
                        }
                    }
                    tx.Commit();
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    tx.Rollback();
                    //throw new Exception(E.Message);
                    return false;
                }
                return true;
            }
        }
        /// <summary>
        /// 执行带一个存储过程参数的的SQL语句。
        /// </summary>
        /// <param name="SQLString">SQL语句</param>
        /// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>
        /// <returns>影响的记录数</returns>
        public static int ExecuteSql(string SQLString, string content)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                SqlCommand cmd = new SqlCommand(SQLString, connection);
                System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@content", SqlDbType.NText);
                myParameter.Value = content;
                cmd.Parameters.Add(myParameter);
                try
                {
                    connection.Open();
                    int rows = cmd.ExecuteNonQuery();
                    return rows;
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    throw new Exception(E.Message);
                }
                finally
                {
                    cmd.Dispose();
                    connection.Close();
                }
            }
        }
        /// <summary>
        /// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
        /// </summary>
        /// <param name="strSQL">SQL语句</param>
        /// <param name="fs">图像字节,数据库的字段类型为image的情况</param>
        /// <returns>影响的记录数</returns>
        public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                SqlCommand cmd = new SqlCommand(strSQL, connection);
                System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@fs", SqlDbType.NText);
                myParameter.Value = fs;
                cmd.Parameters.Add(myParameter);
                try
                {
                    connection.Open();
                    int rows = cmd.ExecuteNonQuery();
                    return rows;
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    throw new Exception(E.Message);
                }
                finally
                {
                    cmd.Dispose();
                    connection.Close();
                }
            }
        }

        /// <summary>
        /// 执行一条计算查询结果语句，返回查询结果（object）。
        /// </summary>
        /// <param name="SQLString">计算查询结果语句</param>
        /// <returns>查询结果（object）</returns>
        public static object GetSingle(string SQLString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                using (SqlCommand cmd = new SqlCommand(SQLString, connection))
                {
                    try
                    {
                        connection.Open();
                        object obj = cmd.ExecuteScalar();
                        if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                        {
                            return null;
                        }
                        else
                        {
                            return obj;
                        }
                    }
                    catch (System.Data.SqlClient.SqlException e)
                    {
                        connection.Close();
                        throw new Exception(e.Message);
                    }
                }
            }
        }

        /// <summary>
        /// 2012-2-21新增重载：执行一条计算查询结果语句，返回查询结果（object）。
        /// </summary>
        public static object GetSingle(SqlConnection connection, SqlTransaction trans, string SQLString)
        {
            using (SqlCommand cmd = new SqlCommand(SQLString, connection))
            {
                try
                {
                    cmd.Connection = connection;
                    cmd.Transaction = trans;
                    object obj = cmd.ExecuteScalar();
                    if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                    {
                        return null;
                    }
                    else
                    {
                        return obj;
                    }
                }
                catch (System.Data.SqlClient.SqlException e)
                {
                    trans.Rollback();
                    throw new Exception(e.Message);
                }
            }
        }

        /// <summary>
        /// 执行查询语句，返回SqlDataReader
        /// </summary>
        /// <param name="strSQL">查询语句</param>
        /// <returns>SqlDataReader</returns>
        public static SqlDataReader ExecuteReader(string strSQL)
        {
            SqlConnection connection = new SqlConnection(connectionString);
            SqlCommand cmd = new SqlCommand(strSQL, connection);
            try
            {
                connection.Open();
                SqlDataReader myReader = cmd.ExecuteReader();
                return myReader;
            }
            catch (System.Data.SqlClient.SqlException e)
            {
                throw new Exception(e.Message);
            }

        }
        /// <summary>
        /// 执行查询语句，返回DataSet
        /// </summary>
        /// <param name="SQLString">查询语句</param>
        /// <returns>DataSet</returns>
        public static DataSet Query(string SQLString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                DataSet ds = new DataSet();
                try
                {
                    connection.Open();
                    SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
                    command.Fill(ds, "ds");
                }
                catch (System.Data.SqlClient.SqlException ex)
                {
                    throw new Exception(ex.Message);
                }
                return ds;
            }
        }

        /// <summary>
        /// 2013-2-21新增,执行查询语句，返回DataSet
        /// </summary>
        public static DataSet Query(SqlConnection connection, SqlTransaction trans, string SQLString)
        {
            DataSet ds = new DataSet();
            try
            {
                SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
                command.SelectCommand.Transaction = trans;
                command.Fill(ds, "ds");
            }
            catch (System.Data.SqlClient.SqlException ex)
            {
                throw new Exception(ex.Message);
            }
            return ds;
        }

  

        #region 执行带参数的SQL语句

        /// <summary>
        /// 执行SQL语句，返回影响的记录数
        /// </summary>
        /// <param name="SQLString">SQL语句</param>
        /// <returns>影响的记录数</returns>
        public static int ExecuteSql(string SQLString, params SqlParameter[] cmdParms)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                using (SqlCommand cmd = new SqlCommand())
                {
                    try
                    {
                        PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                        int rows = cmd.ExecuteNonQuery();
                        cmd.Parameters.Clear();
                        return rows;
                    }
                    catch (System.Data.SqlClient.SqlException E)
                    {
                        throw new Exception(E.Message);
                    }
                }
            }
        }

        /// <summary>
        /// 2012-2-20日新增一条重载方法，方便在DAL层使用事务
        /// </summary>
        /// <param name="connection">SqlConnection对象</param>
        /// <param name="trans">SqlTransaction对象</param>
        /// <param name="SQLString">SQL语句</param>
        /// <param name="cmdParms">SqlParameter对像</param>
        /// <returns>受影响的行</returns>
        public static int ExecuteSql(SqlConnection connection, SqlTransaction trans, string SQLString, params SqlParameter[] cmdParms)
        {
            using (SqlCommand cmd = new SqlCommand())
            {
                try
                {
                    PrepareCommand(cmd, connection, trans, SQLString, cmdParms);
                    int rows = cmd.ExecuteNonQuery();
                    cmd.Parameters.Clear();
                    return rows;
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    //trans.Rollback();
                    throw new Exception(E.Message);
                }
            }
        }

        /// <summary>
        /// 执行多条SQL语句，实现数据库事务。
        /// </summary>
        /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的SqlParameter[]）</param>
        public static bool ExecuteSqlTran(Hashtable SQLStringList)
        {
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                conn.Open();
                using (SqlTransaction trans = conn.BeginTransaction())
                {
                    SqlCommand cmd = new SqlCommand();
                    try
                    {
                        //循环
                        foreach (DictionaryEntry myDE in SQLStringList)
                        {
                            string cmdText = myDE.Key.ToString();
                            SqlParameter[] cmdParms = (SqlParameter[])myDE.Value;
                            PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
                            int val = cmd.ExecuteNonQuery();
                            cmd.Parameters.Clear();
                        }
                        trans.Commit();
                    }
                    catch
                    {
                        trans.Rollback();
                        return false;
                    }
                }
            }
            return true;
        }


        /// <summary>
        /// 执行一条计算查询结果语句，返回查询结果（object）。
        /// </summary>
        /// <param name="SQLString">计算查询结果语句</param>
        /// <returns>查询结果（object）</returns>
        public static object GetSingle(string SQLString, params SqlParameter[] cmdParms)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                using (SqlCommand cmd = new SqlCommand())
                {
                    try
                    {
                        PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                        object obj = cmd.ExecuteScalar();
                        cmd.Parameters.Clear();
                        if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                        {
                            return null;
                        }
                        else
                        {
                            return obj;
                        }
                    }
                    catch (System.Data.SqlClient.SqlException e)
                    {
                        throw new Exception(e.Message);
                    }
                }
            }
        }

        /// <summary>
        /// 执行查询语句，返回SqlDataReader
        /// </summary>
        /// <param name="strSQL">查询语句</param>
        /// <returns>SqlDataReader</returns>
        public static SqlDataReader ExecuteReader(string SQLString, params SqlParameter[] cmdParms)
        {
            SqlConnection connection = new SqlConnection(connectionString);
           SqlCommand cmd = new SqlCommand();
            try
            {
                PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                SqlDataReader myReader = cmd.ExecuteReader();
                cmd.Parameters.Clear();
                return myReader;
            }
            catch (System.Data.SqlClient.SqlException e)
            {
                throw new Exception(e.Message);
            }

        }

        /// <summary>
        /// 执行查询语句，返回DataSet
        /// </summary>
        /// <param name="SQLString">查询语句</param>
        /// <returns>DataSet</returns>
        public static DataSet Query(string SQLString, params SqlParameter[] cmdParms)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
               SqlCommand cmd = new SqlCommand();
                PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                using (SqlDataAdapter da = new SqlDataAdapter(cmd))
                {
                    DataSet ds = new DataSet();
                    try
                    {
                        da.Fill(ds, "ds");
                        cmd.Parameters.Clear();
                    }
                    catch (System.Data.SqlClient.SqlException ex)
                    {
                        throw new Exception(ex.Message);
                    }
                    return ds;
                }
            }
        }

        /// <summary>
        /// 2012-2-21新增结合事务
        /// </summary>
        public static DataSet Query(SqlConnection connection, SqlTransaction trans, string SQLString, params SqlParameter[] cmdParms)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, connection, trans, SQLString, cmdParms);
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
                DataSet ds = new DataSet();
                try
                {
                    da.Fill(ds, "ds");
                    cmd.Parameters.Clear();
                }
                catch (System.Data.SqlClient.SqlException ex)
                {
                    throw new Exception(ex.Message);
                }
                return ds;
            }
        }

        private static void PrepareCommand(SqlCommand cmd, SqlConnection conn,SqlTransaction trans, 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 = CommandType.Text;//cmdType;
            if (cmdParms != null)
            {
                foreach (SqlParameter parm in cmdParms)
                    cmd.Parameters.Add(parm);
            }
        }

        #endregion

        #region 存储过程操作

        /// <summary>
        /// 执行存储过程
        /// </summary>
        /// <param name="storedProcName">存储过程名</param>
        /// <param name="parameters">存储过程参数</param>
        /// <returns>SqlDataReader</returns>
        public static SqlDataReader RunProcedure(string storedProcName, IDataParameter[] parameters)
        {
            SqlConnection connection = new SqlConnection(connectionString);
            SqlDataReader returnReader;
            connection.Open();
            SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters);
            command.CommandType = CommandType.StoredProcedure;
            returnReader = command.ExecuteReader();
            return returnReader;
        }


        /// <summary>
        /// 执行存储过程
        /// </summary>
        /// <param name="storedProcName">存储过程名</param>
        /// <param name="parameters">存储过程参数</param>
        /// <param name="tableName">DataSet结果中的表名</param>
        /// <returns>DataSet</returns>
        public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                DataSet dataSet = new DataSet();
                connection.Open();
                SqlDataAdapter sqlDA = new SqlDataAdapter();
                sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters);
                sqlDA.Fill(dataSet, tableName);
                connection.Close();
                return dataSet;
            }
        }


        /// <summary>
        /// 构建 SqlCommand 对象(用来返回一个结果集，而不是一个整数值)
        /// </summary>
        /// <param name="connection">数据库连接</param>
        /// <param name="storedProcName">存储过程名</param>
        /// <param name="parameters">存储过程参数</param>
        /// <returns>SqlCommand</returns>
        private static SqlCommand BuildQueryCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters)
        {
            SqlCommand command = new SqlCommand(storedProcName, connection);
            command.CommandType = CommandType.StoredProcedure;
            foreach (SqlParameter parameter in parameters)
            {
                command.Parameters.Add(parameter);
            }
            return command;
        }

        /// <summary>
        /// 执行存储过程，返回影响的行数		
        /// </summary>
        /// <param name="storedProcName">存储过程名</param>
        /// <param name="parameters">存储过程参数</param>
        /// <param name="rowsAffected">影响的行数</param>
        /// <returns></returns>
        public static int RunProcedure(string storedProcName, IDataParameter[] parameters, out int rowsAffected)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                int result;
                connection.Open();
                SqlCommand command = BuildIntCommand(connection, storedProcName, parameters);
                rowsAffected = command.ExecuteNonQuery();
                result = (int)command.Parameters["ReturnValue"].Value;
                //Connection.Close();
                return result;
            }
        }

        /// <summary>
        /// 创建 SqlCommand 对象实例(用来返回一个整数值)	
        /// </summary>
        /// <param name="storedProcName">存储过程名</param>
        /// <param name="parameters">存储过程参数</param>
        /// <returns>SqlCommand 对象实例</returns>
        private static SqlCommand BuildIntCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters)
        {
            SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters);
            command.Parameters.Add(new SqlParameter("ReturnValue",
                SqlDbType.Int, 4, ParameterDirection.ReturnValue,
                false, 0, 0, string.Empty, DataRowVersion.Default, null));
            return command;
        }
        #endregion



    //author:Angel_asp
    //QQ：709047174
    //website:www.angelasp.com


}