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

namespace DAL
{
    /// <summary>
    /// 连接数据库类
    /// </summary>
    public class SqlServerDBHelper
    {
        /// <summary>
        /// 连接数据库
        /// </summary>
        /// <returns></returns>
        public static SqlConnection GetConnection()
        {
            string conString = System.Configuration.ConfigurationManager.ConnectionStrings["connstring"].ToString();//定义连接数据库字符集
            return new SqlConnection(conString);//返回连接数据库对象
        }
        /// <summary>
        /// 用数据填充的方法查询
        /// </summary>
        /// <param name="type"></param>
        /// <param name="sql"></param>
        /// <param name="pares"></param>
        /// <returns></returns>
        public DataSet GetDataSet(CommandType type, string sql, params SqlParameter[] pares)
        {
            SqlConnection con = GetConnection();
            DataSet ds = new DataSet();
            SqlDataAdapter da = new SqlDataAdapter(sql, con);
            da.SelectCommand.CommandType = type;
            if (pares != null)
            {
                foreach (SqlParameter pare in pares)
                {
                    da.SelectCommand.Parameters.Add(pare);
                }
            }
            da.Fill(ds);
            return ds;
        }

public DataSet GetDataSet(string sql, params SqlParameter[] pares)
        {
            return GetDataSet(CommandType.Text, sql, pares);
        }

public SqlDataReader GetSqlDataReader(CommandType type, string sql,out SqlConnection con, params SqlParameter[] pares)
        {
            con = GetConnection();
            SqlCommand cmd = new SqlCommand(sql, con);
            cmd.CommandType = type;
            con.Open();
            if (pares != null)
            {
                foreach (SqlParameter pare in pares)
                {
                    cmd.Parameters.Add(pare);
                }
            }
            return cmd.ExecuteReader(CommandBehavior.CloseConnection);
        }

public SqlDataReader GetSqlDataReader(string sql,out SqlConnection con, params SqlParameter[] pares)
        {
            return GetSqlDataReader(CommandType.Text, sql,out con, pares);
        }

public bool MidfyDB(CommandType type, string sql, params SqlParameter[] pares)
        {
            bool falg = false;
            SqlConnection con = GetConnection();
            SqlCommand cmd = new SqlCommand(sql, con);
            cmd.CommandType = type;
            if (pares != null)
            {
                foreach (SqlParameter pare in pares)
                {
                    cmd.Parameters.Add(pare);
                }
            }
            SqlTransaction trans = null;
            try
            {
                con.Open();
                trans = con.BeginTransaction();
                cmd.Transaction = trans;
                cmd.ExecuteNonQuery();
                trans.Commit();
                falg = true;
            }
            catch (Exception e)
            {
                trans.Rollback();
                throw e;
            }
            finally
            {
                con.Close();
            }
            return falg;
        }

public bool MidfyDB(string sql, params SqlParameter[] pares)
        {
            return MidfyDB(CommandType.Text, sql, pares);
        }

/// <summary>
        /// 查询聚合函数类
        /// </summary>
        /// <param name="type">数据库操作的类型 如:StoredProcedure(存储过程)、Text(文本)</param>
        /// <param name="sql">数据库操作字符集</param>
        /// <param name="paras">查询数据库时所用的参数</param>
        /// <returns>object(一般为单个值)</returns>
        public object GetScalar(CommandType type, string sql, params SqlParameter[] paras)
        {
            SqlConnection con = GetConnection();//创建数据集对象
            SqlCommand cmd = new SqlCommand(sql, con);//操作数据库对象
            cmd.CommandType = type;//数据库操作的类型
            //如果参数不为空
            if (paras != null)
            {
                //遍历参数数组
                foreach (SqlParameter para in paras)
                {
                    cmd.Parameters.Add(para);//给操作数据库对象加上参数
                }
            }
            con.Open();//打开数据库连接
            object obj = cmd.ExecuteScalar();//返回一个一行一列的植
            con.Close();//关闭数据库连接
            return obj;
        }

public object GetScalar(string sql, params SqlParameter[] paras)
        {
            return GetScalar(CommandType.Text, sql, paras);
        }

#region 数据填充DataTable

public static DataTable DataFill(SqlCommand cmd)
        {
            DataTable dt = new DataTable();
            cmd.Connection = GetConnection();
            SqlDataAdapter _da = new SqlDataAdapter(cmd);
            _da.Fill(dt);
            return dt;
        }
        #endregion

//public DataTable DateTel(string sql)
        //{
        //    SqlConnection con = GetConnection();
        //    SqlCommand cmd = new SqlCommand(sql, con);
        //    SqlDataAdapter da = new SqlDataAdapter(cmd);
        //    DataTable dt = new DataTable();
        //    da.Fill(dt);
        //    return dt;
        //}

internal DataSet GetDataSet(string sql, int UID)
        {
            throw new NotImplementedException();
        }

public static SqlCommand GetCommand(string text)
        {
            SqlCommand cmdObject = new SqlCommand();
            cmdObject.CommandText = text;
            return cmdObject;
        }

public static void PreparedCommand(SqlCommand cmd, SqlParameter[] pars)
        {
            foreach (SqlParameter p in pars)
            {
                cmd.Parameters.Add(p);
            }
        }
    }
}