C# SQLServer数据库连接并执行类

SQLHelper.cs

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Web;
using System.Web.Configuration;

public class SQLHelper
{
    public static string GetSqlConnectionString()
    {
        //return ConfigurationManager.ConnectionStrings["Sql"].ConnectionString;
            return "Data Source='IP地址';Initial Catalog='数据库';User ID='用户名';Password='密码'";

    }
    //适合增删改操作，返回影响条数
    public static int ExecuteNonQuery(string sql, params SqlParameter[] parameters)
    {
        using (SqlConnection conn = new SqlConnection(GetSqlConnectionString()))
        {
            using (SqlCommand comm = conn.CreateCommand())
            {
                conn.Open();
                comm.CommandText = sql;
                comm.Parameters.AddRange(parameters);
                return comm.ExecuteNonQuery();
            }
        }
    }
    //查询操作，返回查询结果中的第一行第一列的值
    public static object ExecuteScalar(string sql, params SqlParameter[] parameters)
    {
        using (SqlConnection conn = new SqlConnection(GetSqlConnectionString()))
        {
            using (SqlCommand comm = conn.CreateCommand())
            {
                conn.Open();
                comm.CommandText = sql;
                comm.Parameters.AddRange(parameters);
                return comm.ExecuteScalar();
            }
        }
    }
    //Adapter调整，查询操作，返回DataTable
    public static DataTable ExecuteDataTable(string sql, params SqlParameter[] parameters)
    {
        using (SqlDataAdapter adapter = new SqlDataAdapter(sql, GetSqlConnectionString()))
        {
            DataTable dt = new DataTable();
            adapter.SelectCommand.Parameters.AddRange(parameters);
            adapter.Fill(dt);
            return dt;
        }
    }

    public static SqlDataReader ExecuteReader(string sqlText, params SqlParameter[] parameters)
    {
        //SqlDataReader要求，它读取数据的时候有，它独占它的SqlConnection对象，而且SqlConnection必须是Open状态
        SqlConnection conn = new SqlConnection(GetSqlConnectionString());//不要释放连接，因为后面还需要连接打开状态
        SqlCommand cmd = conn.CreateCommand();
        conn.Open();
        cmd.CommandText = sqlText;
        if (parameters != null)
        { 
        cmd.Parameters.AddRange(parameters);
        }
        //CommandBehavior.CloseConnection当SqlDataReader释放的时候，顺便把SqlConnection对象也释放掉
        return cmd.ExecuteReader(CommandBehavior.CloseConnection);
    }

    public static SqlDataReader ExecuteReader1(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
    {
        SqlCommand cmd = new SqlCommand();
        SqlConnection conn = new SqlConnection(GetSqlConnectionString());
        cmd.CommandTimeout = 1800;
        // we use a try/catch here because if the method throws an exception we want to 
        // close the connection throw code, because no datareader will exist, hence the 
        // commandBehaviour.CloseConnection will not work
        try
        {
            PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
            SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
            cmd.Parameters.Clear();
            return rdr;
        }
        catch
        {
            conn.Close();
            throw;
        }
    }

    private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
    {

        if (conn.State != ConnectionState.Open)
            conn.Open();

        cmd.Connection = conn;
        cmd.CommandText = cmdText;

        if (trans != null)
            cmd.Transaction = trans;

        cmd.CommandType = cmdType;

        if (cmdParms != null)
        {
            foreach (SqlParameter parm in cmdParms)
                cmd.Parameters.Add(parm);
        }
    }
}