SQLHelper数据库.net通用类

来源：互联网发布：神硕加人软件编辑：程序博客网时间：2024/04/30 10:22

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

namespace Tskill.Helper
{
    public class SqlHelper
    {
        private SqlConnection conn = null;
        private SqlCommand com = null;
        private SqlDataReader sdr = null;

        /// <summary>
        /// 重构SqlHelper
        /// </summary>
        public SqlHelper()
        {
            string connStr = ConfigurationManager.ConnectionStrings["connString"].ConnectionString;
            if (conn == null)
            {
                conn = new SqlConnection(connStr);   //初始化SqlConnection
            }
        }

        /// <summary>
        /// 获取数据库连接:当数据库连接关闭时，打开连接；再返回连接
        /// </summary>
        /// <returns>返回SqlConnection</returns>
        private SqlConnection GetConn()
        {
            if (conn.State == ConnectionState.Closed)
            {
                conn.Open();
            }
            return conn;
        }

        //打开数据库
        public void Open()
        {
            if (conn.State == ConnectionState.Closed)
            {
                conn.Open();
            }
        }

        //关闭数据库
        public void Close()
        {
            if (conn.State == ConnectionState.Open)
            {
                conn.Close();
            }
        }

        /// <summary>
        /// 该方法执行传入的SQL增、删、改语句
        /// </summary>
        /// <param name="sqlString">要执行的SQL语句</param>
        /// <returns>返回更新的记录数</returns>
        public int ExecuteNonQuery(string sqlString)
        {
            int res = 0;
            using (com = new SqlCommand(sqlString, GetConn()))
            {
                res = com.ExecuteNonQuery();
                conn.Close();
            }
            return res;
        }

        /// <summary>
        /// 该方法执行传入的SQL增删改语句
        /// </summary>
        /// <param name="sqlString">要执行的SQL语句</param>
        /// <returns>返回更新的记录数</returns>
        public int ExecuteNonQuery(string sqlString, List<SqlParameter> listPar)
        {
            int res;   //如果定义为0，后面判断就要注意了
            using (com = new SqlCommand(sqlString, GetConn()))
            {
                com.Parameters.AddRange(listPar.ToArray());
                res = com.ExecuteNonQuery();
                conn.Close();
            }
            return res;
        }

        /// <summary>
        /// 该方法执行传入的SQL查询语句
        /// </summary>
        /// <param name="sqlString">SQL查询语句</param>
        /// <returns>SqlDataReader</returns>
        public SqlDataReader ExecuteReader(string sqlString)
        {
            using (com = new SqlCommand(sqlString, GetConn()))
            {
                sdr = com.ExecuteReader();
            }
            return sdr;

}

        /// <summary>
        /// 该方法执行传入的SQL查询语句
        /// </summary>
        /// <param name="sqlString">SQL查询语句</param>
        /// <returns>SqlDataReader</returns>
        public SqlDataReader ExecuteReader(string sqlString, List<SqlParameter> listPar)
        {
            using (com = new SqlCommand(sqlString, GetConn()))
            {
                com.Parameters.AddRange(listPar.ToArray());
                sdr = com.ExecuteReader();
            }
            return sdr;
        }

        /// <summary>
        /// 该方法执行传入的SQL查询语句
        /// </summary>
        /// <param name="sqlString">SQL查询语句</param>
        /// <returns>DataTable</returns>
        public DataTable DtReader(string sqlString)
        {
            DataTable dt = new DataTable();
            com = new SqlCommand(sqlString, GetConn());
            using (sdr = com.ExecuteReader(CommandBehavior.CloseConnection)) //如果关闭sdr连接，关联的conn连接也将关闭
            {
                dt.Load(sdr);
            }
            return dt;
        }

       /// <summary>
        /// 该方法执行传入的SQL查询语句
        /// </summary>
        /// <param name="sqlString">SQL查询语句</param>
        /// <returns>DataTable</returns>
        public DataSet dsReader(string sql)
        {
            DataSet ds = new DataSet();
            using (SqlDataAdapter sqldap = new SqlDataAdapter(sql, GetConn()))//数据适配器就是一个类 ado.net 提供的我们把.net 平台连库的方式称之为 ado.net "他可以动态添加参数"
            {
                sqldap.Fill(ds);
                Close();
            }
            return ds;
        }

}
}