DBHelper类

1.先在Web.config 文件中加入要连接的数据库

<connectionStrings >
<add name="logisDb" connectionString="Data Source=.;Initial Catalog=logis;Integrated Security=True"/>
</connectionStrings>
————————————————

2.编写DBHelper类
先引入命名空间：using System.Configuration;

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data;
using System.Data.SqlClient;
using System.Data.Sql;
using System.Configuration;
namespace HP_DAL
{
public class DBHelper
{
/// <summary>
/// 连接字符串
/// </summary>
private readonly static string config = ConfigurationManager.ConnectionStrings["logisDb"].ConnectionString;
/// <summary>
/// 离线查询，返回DataTable
/// </summary>
/// <param name="sql"></param>
/// <param name="par"></param>
/// <returns></returns>
public static DataTable ExecuteTable(string sql,params SqlParameter[] par)
{
using (SqlDataAdapter sda = new SqlDataAdapter(sql, config))
{
if (par != null && par.Length > 0)
{
sda.SelectCommand.Parameters.AddRange(par);
}
DataTable dt = new DataTable();
sda.Fill(dt);
return dt;
}

}
/// <summary>
/// 查询首行首列，返回object
/// </summary>
/// <param name="sql"></param>
/// <param name="par"></param>
/// <returns></returns>
public static object ExecuteScalar(string sql, params SqlParameter[] par)
{
using (SqlConnection con = new SqlConnection(config))
{
using (SqlCommand com = new SqlCommand(sql, con))
{
if (par != null && par.Length > 0)
{
com.Parameters.AddRange(par);
}
if (con.State!=ConnectionState.Open)
{
con.Open();
}
return com.ExecuteScalar();
}
}
}
/// <summary>
/// 在线查询，返回SqlDataReader，存储过程
/// </summary>
/// <param name="sql"></param>
/// <param name="par"></param>
/// <returns></returns>
public static SqlDataReader ExecuteReader1(string procname, params SqlParameter[] par)
{
SqlConnection con = new SqlConnection(config);

using (SqlCommand com = new SqlCommand(procname, con))
{
com.CommandType = CommandType.StoredProcedure;
if (par != null && par.Length > 0)
{
com.Parameters.AddRange(par);
}
if (con.State != ConnectionState.Open)
{
con.Open();
}
return com.ExecuteReader(CommandBehavior.CloseConnection);

}
}
/// <summary>
/// 在线查询，返回SqlDataReader
/// </summary>
/// <param name="sql"></param>
/// <param name="par"></param>
/// <returns></returns>
public static SqlDataReader ExecuteReader(string procname, params SqlParameter[] par)
{
SqlConnection con = new SqlConnection(config);

using (SqlCommand com = new SqlCommand(procname, con))
{

if (par != null && par.Length > 0)
{
com.Parameters.AddRange(par);
}
if (con.State != ConnectionState.Open)
{
con.Open();
}
return com.ExecuteReader(CommandBehavior.CloseConnection);

}
}
/// <summary>
/// 增删改方法
/// </summary>
/// <param name="sql"></param>
public static int ExecuteNonQuery(string sql, params SqlParameter[] par)
{
using (SqlConnection con = new SqlConnection(config))
{
using (SqlCommand com = new SqlCommand(sql, con))
{
if (par != null && par.Length > 0)
{
com.Parameters.AddRange(par);
}
if (con.State != ConnectionState.Open)
{
con.Open();
}
return com.ExecuteNonQuery();
}
}
}
/// <summary>
/// 增删改方法，存储过程
/// </summary>
/// <param name="sql"></param>
/// <param name="par"></param>
/// <returns></returns>
public static int ExecuteNonQueryProc(string sql, params SqlParameter[] par)
{
using (SqlConnection con = new SqlConnection(config))
{
using (SqlCommand com = new SqlCommand(sql, con))
{
com.CommandTimeout = 60;
com.CommandType = CommandType.StoredProcedure;
if (par != null && par.Length > 0)
{
com.Parameters.AddRange(par);
}
if (con.State != ConnectionState.Open)
{
con.Open();
}
return com.ExecuteNonQuery();
}
}
}
}
}

DBHelper类

原文：https://www.cnblogs.com/shcLenmon/p/12547986.html