.NET VS 訪問數據庫基類

1、配置文件APP.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <add key="sqlconn" value="Data Source=.; DataBase=db_SAIC; User ID=sa; Password=WIPsys8818;Connect Timeout=2500" />
  </appSettings>
</configuration>

2、DataSource 類

添加引用 System.Configuration

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

namespace Saic.Class
{
    class DataSource
    {
        //訪問配置文件
        public static string connString = ConfigurationManager.AppSettings["sqlconn"];
        public static SqlConnection connection = new SqlConnection(connString);
        //數據庫操做,返回記錄數
        public int ExecuteSqlGetCount(string strSql)
        {

            using (SqlCommand cmd = new SqlCommand(strSql, connection))
            {
                try
                {
                    if (connection.State == ConnectionState.Closed)
                    {
                        connection.Open();
                    }

                    int rows = (int)cmd.ExecuteScalar();

                    return rows;
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    throw new Exception(E.Message);
                }
                finally
                {
                    connection.Close();
                }
               
            }

        }
        //返回數據集
        public DataTable ExecuteSqlGetUser(string strSql)
        {
            using (SqlCommand cmd = new SqlCommand(strSql, connection))
            {
                try
                {
                    if (connection.State == ConnectionState.Closed)
                    {
                        connection.Open();
                    }
                    DataTable dt = new DataTable();
                    SqlDataAdapter sda = new SqlDataAdapter();
                    sda.SelectCommand = cmd;
                    sda.Fill(dt);
                    connection.Close();
                    return dt;
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    throw new Exception(E.Message);
                }
                finally
                {
                    connection.Close();
                }
            }
        }

        //用於返回單行結果
        public  string ExecuteOne(string strSql)
        {
            using (SqlCommand cmd = new SqlCommand(strSql, connection))
            {
                try
                {
                    if (connection.State == ConnectionState.Closed)
                    {
                        connection.Open();
                    }
                    //ExecuteScalar() 執行查詢方法,返回單個值
                    string result;
                    if (cmd.ExecuteScalar() != null)
                    {

                        result = cmd.ExecuteScalar().ToString();
                    }
                    else {
                        result = null;
                    }
                   
                    connection.Close();
                    return result;
                }
                catch (SqlException ex)
                {
                    throw new Exception(ex.Message);
                }
                finally
                {
                    connection.Close();
                }
            }
        }
        

        //增刪
        public int ExecuteSqlUpdate(string strSql)
        {
            using (SqlCommand cmd = new SqlCommand(strSql, connection))
            {
                try
                {
                    if (connection.State == ConnectionState.Closed)
                    {
                        connection.Open();
                    }
                    int rows = cmd.ExecuteNonQuery();
                    connection.Close();
                    return rows;
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    throw new Exception(E.Message);
                }
                finally
                {
                    connection.Close();
                }
            }
        }

        //調用SQL存儲過程 Proc_BS
        public int ExecuteProcGetParm(string strProc, int scaleC, int scaleAB, int scaleC_1, int scaleAB_1)
        {
            using (SqlCommand cmd = new SqlCommand(strProc, connection))
            {
                try
                {
                    cmd.CommandTimeout = 0;
                    cmd.CommandText = strProc;// "Proc_BS";
                    cmd.CommandType = CommandType.StoredProcedure;


                    SqlParameter parm = cmd.Parameters.Add("@scaleC", SqlDbType.Int);
                    parm.Value = scaleC;

                    parm = cmd.Parameters.Add("@scaleAB", SqlDbType.Int);
                    parm.Value = scaleAB;

                    parm = cmd.Parameters.Add("@scaleC_1", SqlDbType.Int);
                    parm.Value = scaleC_1;

                    parm = cmd.Parameters.Add("@scaleAB_1", SqlDbType.Int);
                    parm.Value = scaleAB_1;

                    parm = cmd.Parameters.Add("@rowcount", SqlDbType.Int);
                    parm.Direction = ParameterDirection.Output;

                    if (connection.State == ConnectionState.Closed)
                    {
                        connection.Open();
                        SqlDataReader dr = cmd.ExecuteReader();
                        int rows = int.Parse(cmd.Parameters["@rowcount"].Value.ToString()); //cmd.ExecuteNonQuery();
                        connection.Close();
                        return rows;
                    }

                    return 0;
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    throw new Exception(E.Message);
                }
                finally
                {
                    connection.Close();
                }
            }
        }

    }
}