SQLHelper

来源：互联网发布：图解网络硬件 kindle 编辑：程序博客网时间：2024/05/01 01:15
数据库帮助类基本每个程序都会用到,我上网找了很多个,并进行对比,找到一个比较喜欢的,据说是来自一个叫牛腩新闻系统的开源项目,我对其进行了一些小修改
using System;using System.Collections.Generic;using System.Configuration;using System.Data;using System.Data.SqlClient;using System.Linq;using System.Text;namespace CSJWebApp.BLL{    public class SQLHelper    {        #region 0.1 声明数据数据库连接所需要的对象        private SqlConnection conn = null;        private SqlCommand cmd = null;        private SqlDataReader sdr = null;        #endregion        #region 0.2 构造函数,初始化了连接对象  SQLHelper()        /// <summary>        /// 将连接数据对象封装到构造函数中        /// </summary>        public SQLHelper()        {            string connStr = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;            conn = new SqlConnection(connStr);        }        #endregion        #region 0.3 获取连接对象  GetConn()        /// <summary>        /// 得到连接数据库对象，抽象连接的过程        /// </summary>        /// <returns>返回一个连接数据对象</returns>        private SqlConnection GetConn()        {            if (conn.State == ConnectionState.Closed)            {                conn.Open();            }            return conn;        }        #endregion        #region 1.1 执行增/删/改语句,返回受影响行数  int ExecuteNonQuery(string strsql, CommandType cmdtype, SqlParameter[] paras)        /// <summary>        /// (带参数)执行增/删/改语句,返回受影响行数        /// </summary>        /// <param name="strsql">SQL语句</param>        /// <param name="paras">参数数组</param>        /// <param name="cmdtype">命令类型</param>        /// <returns>返回受影响的行数</returns>        public int ExecuteNonQuery(string sql, CommandType cmdtype, SqlParameter[] paras)        {            int res = 0;            using (cmd = new SqlCommand(sql, GetConn()))            {                try                {                    cmd.CommandType = cmdtype;                    if (paras != null) cmd.Parameters.AddRange(paras);                    res = cmd.ExecuteNonQuery();                }                catch (Exception ex)                {                    if (conn.State == ConnectionState.Open)                    {                        conn.Close();                    }                    throw ex;                }            }            return res;        }        #endregion        #region 2.1 执行查询语句或存储过程,返回DataTable类型的数据  DataTable ExecuteQuery(string sql, CommandType cmdtype, SqlParameter[] paras)        /// <summary>        /// 执行查询语句或存储过程,返回DataTable类型的数据        /// </summary>        /// <param name="sql">SQL语句或者存储过程</param>        /// <param name="cmdtype">命令类型</param>        /// <param name="paras">参数数组</param>        /// <returns>返回DataTable类型的数据</returns>        public DataTable ExecuteQuery(string sql, CommandType cmdtype, SqlParameter[] paras)        {            DataTable dt = new DataTable();            cmd = new SqlCommand(sql, GetConn());            cmd.CommandType = cmdtype;            if (paras != null) cmd.Parameters.AddRange(paras);            using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))            {                dt.Load(sdr);            }            return dt;        }        #endregion        #region 2.2 执行查询语句或存储过程,返回第一行第一列的值  DataTable ExecuteScalar(string sql, CommandType cmdtype, SqlParameter[] paras)        /// <summary>        /// 执行查询语句或存储过程,返回第一行第一列的值        /// </summary>        /// <param name="sql">SQL语句或者存储过程</param>        /// <param name="cmdtype">命令类型</param>        /// <param name="paras">参数数组</param>        /// <returns>返回第一行第一列的值</returns>        public object ExecuteScalar(string sql, CommandType cmdtype, SqlParameter[] paras)        {            object res = null;            using (cmd = new SqlCommand(sql, GetConn()))            {                cmd.CommandType = cmdtype;                try                {                    if (paras != null) cmd.Parameters.AddRange(paras);                    res = cmd.ExecuteScalar();                }                catch (Exception ex)                {                    if (conn.State == ConnectionState.Open)                    {                        conn.Close();                    }                    throw ex;                }            }            return res;        }        #endregion    }}
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