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

namespace CallCenterApi.DB { 

public class DBOracleHelper
{
    public static OracleCommand cmd = null;
    public static OracleConnection conn = null;
    public static string connstr = ConfigurationManager.ConnectionStrings["oracleconn"].ConnectionString;
    public DBOracleHelper()
    { }
    #region 建立数据库连接对象
    /// <summary>
    /// 建立数据库连接
    /// </summary>
    /// <returns>返回一个数据库的连接OracleConnection对象</returns>
    public static OracleConnection init()
    {
        try
        {
            conn = new OracleConnection(connstr);
            if (conn.State != ConnectionState.Open)
            {
                conn.Open();
            }
        }
        catch (Exception e)
        {
            throw new Exception(e.Message.ToString());
        }
        return conn;
    }
    #endregion

    #region 设置OracleCommand对象
    /// <summary>
    /// 设置OracleCommand对象
    /// </summary>
    /// <param name="cmd">OracleCommand对象 </param>
    /// <param name="cmdText">命令文本</param>
    /// <param name="cmdType">命令类型</param>
    /// <param name="cmdParms">参数集合</param>
    private static void SetCommand(OracleCommand cmd, string cmdText, CommandType cmdType, OracleParameter[] cmdParms)
    {
        cmd.Connection = conn;
        cmd.CommandText = cmdText;
        cmd.CommandType = cmdType;
        if (cmdParms != null)
        {
            cmd.Parameters.AddRange(cmdParms);
        }
    }
    #endregion

    #region 执行相应的sql语句，返回相应的DataSet对象
    /// <summary>
    /// 执行相应的sql语句，返回相应的DataSet对象
    /// </summary>
    /// <param name="sqlstr">sql语句</param>
    /// <returns>返回相应的DataSet对象</returns>
    public static DataSet GetDataSet(string sqlstr, OracleParameter[] cmdParms=null)
    {
        DataSet set = new DataSet();
        try
        {
                OracleCommand cmd = new OracleCommand();
                PrepareCommand(cmd, init(), null, sqlstr, cmdParms);
                OracleDataAdapter adp = new OracleDataAdapter(cmd);
            adp.Fill(set);
            conn.Close();
        }
        catch (Exception e)
        {
            throw new Exception(e.Message.ToString());
        }
        return set;
    }

        /// <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 OracleParameter[] cmdParms)
        {
            using (OracleConnection connection = new OracleConnection(connstr))
            {
                OracleCommand cmd = new OracleCommand();
                PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                using (OracleDataAdapter da = new OracleDataAdapter(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(OracleCommand cmd, OracleConnection conn, OracleTransaction trans, string cmdText, OracleParameter[] 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 (OracleParameter parameter in cmdParms)
                {
                    if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) &&
                        (parameter.Value == null))
                    {
                        parameter.Value = DBNull.Value;
                    }
                    cmd.Parameters.Add(parameter);
                }
            }
        }

        #endregion

        #region 执行相应的sql语句，返回相应的DataSet对象
        /// <summary>
        /// 执行相应的sql语句，返回相应的DataSet对象
        /// </summary>
        /// <param name="sqlstr">sql语句</param>
        /// <param name="tableName">表名</param>
        /// <returns>返回相应的DataSet对象</returns>
        public static DataSet GetDataSet(string sqlstr, string tableName)
    {
        DataSet set = new DataSet();
        try
        {
            init();
            OracleDataAdapter adp = new OracleDataAdapter(sqlstr, conn);
            adp.Fill(set, tableName);
            conn.Close();
        }
        catch (Exception e)
        {
            throw new Exception(e.Message.ToString());
        }
        return set;
    }
    #endregion

    #region 执行不带参数sql语句，返回所影响的行数
    /// <summary>
    /// 执行不带参数sql语句，返回所影响的行数
    /// </summary>
    /// <param name="cmdstr">增，删，改sql语句</param>
    /// <returns>返回所影响的行数</returns>
    public static int ExecuteNonQuery(string cmdText)
    {
        int count;
        try
        {
            init();
            cmd = new OracleCommand(cmdText, conn);
            count = cmd.ExecuteNonQuery();
            conn.Close();
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message.ToString());
        }
        return count;
    }
    #endregion

    #region 执行带参数sql语句或存储过程，返回所影响的行数
    /// <summary>
    /// 执行带参数sql语句或存储过程，返回所影响的行数
    /// </summary>
    /// <param name="cmdText">带参数的sql语句和存储过程名</param>
    /// <param name="cmdType">命令类型</param>
    /// <param name="cmdParms">参数集合</param>
    /// <returns>返回所影响的行数</returns>
    public static int ExecuteNonQuery(string cmdText, CommandType cmdType, OracleParameter[] cmdParms)
    {
        int count;
        try
        {
            init();
            cmd = new OracleCommand();
            SetCommand(cmd, cmdText, cmdType, cmdParms);
            count = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            conn.Close();
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message.ToString());
        }
        return count;
    }
    #endregion

    #region 执行不带参数sql语句，返回一个从数据源读取数据的OracleDataReader对象
    /// <summary>
    /// 执行不带参数sql语句，返回一个从数据源读取数据的OracleDataReader对象
    /// </summary>
    /// <param name="cmdstr">相应的sql语句</param>
    /// <returns>返回一个从数据源读取数据的OracleDataReader对象</returns>
    public static OracleDataReader ExecuteReader(string cmdText)
    {
        OracleDataReader reader;
        try
        {
            init();
            cmd = new OracleCommand(cmdText, conn);
            reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);

        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message.ToString());
        }
        return reader;
    }
    #endregion

    #region 执行带参数的sql语句或存储过程，返回一个从数据源读取数据的OracleDataReader对象
    /// <summary>
    /// 执行带参数的sql语句或存储过程，返回一个从数据源读取数据的OracleDataReader对象
    /// </summary>
    /// <param name="cmdText">sql语句或存储过程名</param>
    /// <param name="cmdType">命令类型</param>
    /// <param name="cmdParms">参数集合</param>
    /// <returns>返回一个从数据源读取数据的OracleDataReader对象</returns>
    public static OracleDataReader ExecuteReader(string cmdText, CommandType cmdType, OracleParameter[] cmdParms)
    {
        OracleDataReader reader;
        try
        {
            init();
            cmd = new OracleCommand();
            SetCommand(cmd, cmdText, cmdType, cmdParms);
            reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message.ToString());
        }
        return reader;
    }
    #endregion

    #region 执行不带参数sql语句,返回结果集首行首列的值object
    /// <summary>
    /// 执行不带参数sql语句,返回结果集首行首列的值object
    /// </summary>
    /// <param name="cmdstr">相应的sql语句</param>
    /// <returns>返回结果集首行首列的值object</returns>
    public static object GetSingle(string cmdText)
    {
        object obj;
        try
        {
            init();
            cmd = new OracleCommand(cmdText, conn);
            obj = cmd.ExecuteScalar();
            conn.Close();
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message.ToString());
        }
        return obj;
    }
    #endregion

    #region 执行带参数sql语句或存储过程,返回结果集首行首列的值object
    /// <summary>
    /// 执行带参数sql语句或存储过程,返回结果集首行首列的值object
    /// </summary>
    /// <param name="cmdText">sql语句或存储过程名</param>
    /// <param name="cmdType">命令类型</param>
    /// <param name="cmdParms">返回结果集首行首列的值object</param>
    /// <returns></returns>
    public static object ExecuteScalar(string cmdText, CommandType cmdType, OracleParameter[] cmdParms)
    {
        object obj;
        try
        {
            init();
            cmd = new OracleCommand();
            SetCommand(cmd, cmdText, cmdType, cmdParms);
            obj = cmd.ExecuteScalar();
            conn.Close();
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message.ToString());
        }
        return obj;
    }
    #endregion





}
}