ADO.NET帮助类DBHelper

一. DBHelper帮助类

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Data;

using System.Data.SqlClient;

using System.Configuration;

namespace DAL

{

    /// <summary>

    /// 数据库操作帮助类

    /// </summary>

    public class DBHelper

    {

        //连接字符串,从web.config中获取

        public static string conStr = ConfigurationManager.ConnectionStrings["DBConnectionString1"].ConnectionString;

        /// <summary>

        /// 获取SqlCommand对象

        /// </summary>

        /// <param name="sql">sql语句</param>

        /// <param name="conn">数据库连接对象</param>

        /// <param name="pars">参数集</param>

        /// <returns>SqlCommand对象</returns>

        private static SqlCommand GetSqlCommand(string sql, SqlConnection conn, params SqlParameter[] pars)

        {

            conn.Open();

            SqlCommand comm = new SqlCommand(sql, conn);

            comm.Parameters.AddRange(pars);

            return comm;

        }

        /// <summary>

        /// 设置SqlCommand对象的值

        /// </summary>

        /// <param name="comm">SqlCommand对象</param>

        /// <param name="commandText">需要执行的sql语句或存储过程名称</param>

        /// <param name="conn">数据库连接对象</param>

        /// <param name="type">执行的类型(sql语句类型或存储过程类型)</param>

        private static void SetSqlCommand(SqlCommand comm, string commandText, SqlConnection conn, CommandType type)

        {

            comm.CommandText = commandText;

            comm.Connection = conn;

            comm.CommandType = type;

        }

        /// 查询返回SqlDataReader,读取数据完毕后必须关闭SqlDataReader，会自动释放数据库连接

        /// </summary>

        /// <param name="sql">sql语句</param>

        /// <param name="pars">参数集</param>

        /// <returns>SqlDataReader</returns>

        public static SqlDataReader ExecuteReader(string sql, params SqlParameter[] pars)

        {

            SqlConnection conn = new SqlConnection(conStr);

            SqlCommand comm = GetSqlCommand(sql, conn, pars);

            return comm.ExecuteReader(CommandBehavior.CloseConnection);

        }

        /// <summary>

        /// 执行查询，返回结果集的第一行第一列数据

        /// </summary>

        /// <param name="sql">sql语句</param>

        /// <param name="pars">参数集</param>

        /// <returns>单个数据</returns>

        public static object ExecuteScalar(string sql, params SqlParameter[] pars)

        {

            using (SqlConnection conn = new SqlConnection(conStr))

            {

                SqlCommand comm = GetSqlCommand(sql, conn, pars);

                return comm.ExecuteScalar();

            }

        }

        /// <summary>

        /// 执行增删改操作

        /// </summary>

        /// <param name="sql">sql语句</param>

        /// <param name="pars">参数集</param>

        /// <returns>受影响的行数</returns>

        public static int ExecuteNonQuery(string sql, params SqlParameter[] pars)

        {

            using (SqlConnection conn = new SqlConnection(conStr))

            {

                SqlCommand comm = GetSqlCommand(sql, conn, pars);

                return comm.ExecuteNonQuery();

            }

        }

        /// <summary>

        /// 执行查询语句,返回DataTable

        /// </summary>

        /// <param name="sql">sql语句</param>        

        /// <param name="pars">参数集</param>

        /// <returns>DataTable</returns>

        public static DataTable ExecuteAdapter(string sql, params SqlParameter[] pars)

        {

            DataTable dt = new DataTable();

            using (SqlConnection conn = new SqlConnection(conStr))

            {

                SqlDataAdapter adapter = new SqlDataAdapter(sql, conn);

                adapter.SelectCommand.Parameters.AddRange(pars);

                adapter.Fill(dt);

            }

            return dt;

        }

        /// 调用存储过程返回SqlDataReader,读取数据完毕后必须关闭SqlDataReader，会自动释放数据库连接

        /// </summary>

        /// <param name="procedureName">存储过程名称</param>

        /// <param name="comm">Sqlcommand对象</param>

        /// <returns>SqlDataReader</returns>

        public static SqlDataReader ExecuteReader(string procedureName, SqlCommand comm)

        {

            SqlConnection conn = new SqlConnection(conStr);

            SetSqlCommand(comm, procedureName, conn, CommandType.StoredProcedure);

            return comm.ExecuteReader(CommandBehavior.CloseConnection);

        }

        /// <summary>

        /// 调用存储过程，返回结果集的第一行第一列数据

        /// </summary>

        /// <param name="procedureName">存储过程名称</param>

        /// <param name="comm">Sqlcommand对象</param>

        /// <returns>单个数据</returns>

        public static object ExecuteScalar(string procedureName, SqlCommand comm)

        {

            using (SqlConnection conn = new SqlConnection(conStr))

            {

                SetSqlCommand(comm, procedureName, conn, CommandType.StoredProcedure);

                return comm.ExecuteScalar();

            }

        }

        /// <summary>

        /// 调用存储过程，执行非查询操作(增删改)

        /// </summary>

        /// <param name="procedureName">存储过程名称</param>

        /// <param name="comm">Sqlcommand对象</param>

        /// <returns>受影响的行数</returns>

        public static int ExecuteNonQuery(string procedureName, SqlCommand comm)

        {

            using (SqlConnection conn = new SqlConnection(conStr))

            {

                SetSqlCommand(comm, procedureName, conn, CommandType.StoredProcedure);

                return comm.ExecuteNonQuery();

            }

        }

        /// <summary>

        /// 执行存储过程,返回DataTable

        /// </summary>

        /// <param name="procedureName">存储过程名称</param>

        /// <param name="comm">Sqlcommand对象</param>

        /// <returns>DataTable</returns>

        public static DataTable ExecuteAdapter(string procedureName, SqlCommand comm)

        {

            DataTable dt = new DataTable();

            using (SqlConnection conn = new SqlConnection(conStr))

            {

                SetSqlCommand(comm, procedureName, conn, CommandType.StoredProcedure);

                SqlDataAdapter adapter = new SqlDataAdapter(comm);

                adapter.Fill(dt);

            }

            return dt;

        }

        /// <summary>

        /// 使用事务执行多个非查询操作，sql语句不能相同

        /// </summary>

        /// <param name="sqlList">键：sql语句  值：参数集</param>

        /// <returns>是否全都成功执行</returns>

        public static bool ExecuteWithTransaction(Dictionary<string, List<SqlParameter>> sqlList)

        {

            using (SqlConnection conn = new SqlConnection(conStr))

            {

                conn.Open();

                SqlTransaction tran = conn.BeginTransaction();

                SqlCommand comm = new SqlCommand();

                comm.Connection = conn;

                comm.Transaction = tran;

                try

                {

                    foreach (var v in sqlList)

                    {

                        comm.Parameters.Clear();

                        comm.CommandText = v.Key;

                        if (v.Value != null && v.Value.Count > )

                        {

                            comm.Parameters.AddRange(v.Value.ToArray());

                        }

                        comm.ExecuteNonQuery();

                    }

                    tran.Commit();

                    return true;

                }

                catch (Exception)

                {

                    tran.Rollback();

                    return false;

                }

            }

        }

        /// <summary>

        /// 使用事务执行多个非查询操作，通用

        /// </summary>

        /// <param name="sqlList">SQL对象</param>

        /// <returns>是否全都成功执行</returns>

        public static bool ExecuteWithTransaction(List<SQL> sqlList)

        {

            using (SqlConnection conn = new SqlConnection(conStr))

            {

                conn.Open();

                SqlTransaction tran = conn.BeginTransaction();

                SqlCommand comm = new SqlCommand();

                comm.Connection = conn;

                comm.Transaction = tran;

                try

                {

                    foreach (var v in sqlList)

                    {

                        comm.Parameters.Clear();

                        comm.CommandText = v.Sql;

                        if (v.ParameterList != null && v.ParameterList.Count > )

                        {

                            comm.Parameters.AddRange(v.ParameterList.ToArray());

                        }

                        comm.ExecuteNonQuery();

                    }

                    tran.Commit();

                    return true;

                }

                catch (Exception)

                {

                    tran.Rollback();

                    return false;

                }

            }

        }

    }

    /// <summary>

    /// SQL类,包含sql语句和参数集

    /// </summary>

    public class SQL

    {

        public string Sql { get; set; }

        public List<SqlParameter> ParameterList { get; set; }

        public SQL(string sql, List<SqlParameter> pars)

        {

            this.Sql = sql;

            this.ParameterList = pars;

        }

        public SQL(string sql)

        {

            this.Sql = sql;

        }

        public SQL()

        {

        }

    }

}

二.例子
    存储过程

alter proc p_getByGender

    @Gender char()=,

    @Count int output

as

    declare @CountSql nvarchar()

    set @CountSql='select @Count=count(1) from Student'

    exec sp_executesql @CountSql,N'@Count int output',@Count output

    declare @Sql nvarchar()

    set @Sql='select * from Student where Gender = '+CHAR()+@Gender+CHAR()

    print @Gender

    print @Sql

    exec(@Sql)

go

ADO.net调用

        //创建SqlCommand对象

                SqlCommand comm = new SqlCommand();

                //设置存储过程的参数

                comm.Parameters.Add("@Count", SqlDbType.Int).Direction = ParameterDirection.Output;

                comm.Parameters.Add("@Gender", SqlDbType.Char, ).Value = ;

                //调用DBHelper的方法返回结果

                DataTable dt=DBHelper.ExecuteAdapter("p_getByGender", comm);

                //储存过程的输出参数

                int count = (int)comm.Parameters["@Count"].Value;