using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
namespace HelloWinForm.DBUtility
{
class SQLHelper
{
#region 通用方法
// 數(shù)據(jù)連接池
private SqlConnection con;
/// <summary>
/// 返回數(shù)據(jù)庫連接字符串
/// </summary>
/// <returns></returns>
public static String GetSqlConnection()
{
String conn = ConfigurationManager.AppSettings["connectionString"].ToString();
return conn;
}
#endregion
#region 執(zhí)行sql字符串
/// <summary>
/// 執(zhí)行不帶參數(shù)的SQL語句
/// </summary>
/// <param name="Sqlstr"></param>
/// <returns></returns>
public static int ExecuteSql(String Sqlstr)
{
String ConnStr = GetSqlConnection();
using (SqlConnection conn = new SqlConnection(ConnStr))
{
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandText = Sqlstr;
conn.Open();
cmd.ExecuteNonQuery();
conn.Close();
return 1;
}
}
/// <summary>
/// 執(zhí)行帶參數(shù)的SQL語句
/// </summary>
/// <param name="Sqlstr">SQL語句</param>
/// <param name="param">參數(shù)對象數(shù)組</param>
/// <returns></returns>
public static int ExecuteSql(String Sqlstr, SqlParameter[] param)
{
String ConnStr = GetSqlConnection();
using (SqlConnection conn = new SqlConnection(ConnStr))
{
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandText = Sqlstr;
cmd.Parameters.AddRange(param);
conn.Open();
cmd.ExecuteNonQuery();
conn.Close();
return 1;
}
}
/// <summary>
/// 返回DataReader
/// </summary>
/// <param name="Sqlstr"></param>
/// <returns></returns>
public static SqlDataReader ExecuteReader(String Sqlstr)
{
String ConnStr = GetSqlConnection();
SqlConnection conn = new SqlConnection(ConnStr);//返回DataReader時,是不可以用using()的
try
{
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandText = Sqlstr;
conn.Open();
return cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection);//關(guān)閉關(guān)聯(lián)的Connection
}
catch //(Exception ex)
{
return null;
}
}
/// <summary>
/// 執(zhí)行SQL語句并返回數(shù)據(jù)表
/// </summary>
/// <param name="Sqlstr">SQL語句</param>
/// <returns></returns>
public static DataTable ExecuteDt(String Sqlstr)
{
String ConnStr = GetSqlConnection();
using (SqlConnection conn = new SqlConnection(ConnStr))
{
SqlDataAdapter da = new SqlDataAdapter(Sqlstr, conn);
DataTable dt = new DataTable();
conn.Open();
da.Fill(dt);
conn.Close();
return dt;
}
}
/// <summary>
/// 執(zhí)行SQL語句并返回DataSet
/// </summary>
/// <param name="Sqlstr">SQL語句</param>
/// <returns></returns>
public static DataSet ExecuteDs(String Sqlstr)
{
String ConnStr = GetSqlConnection();
using (SqlConnection conn = new SqlConnection(ConnStr))
{
SqlDataAdapter da = new SqlDataAdapter(Sqlstr, conn);
DataSet ds = new DataSet();
conn.Open();
da.Fill(ds);
conn.Close();
return ds;
}
}
#endregion
#region 操作存儲過程
/// <summary>
/// 運行存儲過程(已重載)
/// </summary>
/// <param name="procName">存儲過程的名字</param>
/// <returns>存儲過程的返回值</returns>
public int RunProc(string procName)
{
SqlCommand cmd = CreateCommand(procName, null);
cmd.ExecuteNonQuery();
this.Close();
return (int)cmd.Parameters["ReturnValue"].Value;
}
/// <summary>
/// 運行存儲過程(已重載)
/// </summary>
/// <param name="procName">存儲過程的名字</param>
/// <param name="prams">存儲過程的輸入?yún)?shù)列表</param>
/// <returns>存儲過程的返回值</returns>
public int RunProc(string procName, SqlParameter[] prams)
{
SqlCommand cmd = CreateCommand(procName, prams);
cmd.ExecuteNonQuery();
this.Close();
return (int)cmd.Parameters[0].Value;
}
/// <summary>
/// 運行存儲過程(已重載)
/// </summary>
/// <param name="procName">存儲過程的名字</param>
/// <param name="dataReader">結(jié)果集</param>
public void RunProc(string procName, out SqlDataReader dataReader)
{
SqlCommand cmd = CreateCommand(procName, null);
dataReader = cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection);
}
/// <summary>
/// 運行存儲過程(已重載)
/// </summary>
/// <param name="procName">存儲過程的名字</param>
/// <param name="prams">存儲過程的輸入?yún)?shù)列表</param>
/// <param name="dataReader">結(jié)果集</param>
public void RunProc(string procName, SqlParameter[] prams, out SqlDataReader dataReader)
{
SqlCommand cmd = CreateCommand(procName, prams);
dataReader = cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection);
}
/// <summary>
/// 創(chuàng)建Command對象用于訪問存儲過程
/// </summary>
/// <param name="procName">存儲過程的名字</param>
/// <param name="prams">存儲過程的輸入?yún)?shù)列表</param>
/// <returns>Command對象</returns>
private SqlCommand CreateCommand(string procName, SqlParameter[] prams)
{
// 確定連接是打開的
Open();
//command = new SqlCommand( sprocName, new SqlConnection( ConfigManager.DALConnectionString ) );
SqlCommand cmd = new SqlCommand(procName, con);
cmd.CommandType = CommandType.StoredProcedure;
// 添加存儲過程的輸入?yún)?shù)列表
if (prams != null)
{
foreach (SqlParameter parameter in prams)
cmd.Parameters.Add(parameter);
}
// 返回Command對象
return cmd;
}
/// <summary>
/// 創(chuàng)建輸入?yún)?shù)
/// </summary>
/// <param name="ParamName">參數(shù)名</param>
/// <param name="DbType">參數(shù)類型</param>
/// <param name="Size">參數(shù)大小</param>
/// <param name="Value">參數(shù)值</param>
/// <returns>新參數(shù)對象</returns>
public SqlParameter MakeInParam(string ParamName, SqlDbType DbType, int Size, object Value)
{
return MakeParam(ParamName, DbType, Size, ParameterDirection.Input, Value);
}
/// <summary>
/// 創(chuàng)建輸出參數(shù)
/// </summary>
/// <param name="ParamName">參數(shù)名</param>
/// <param name="DbType">參數(shù)類型</param>
/// <param name="Size">參數(shù)大小</param>
/// <returns>新參數(shù)對象</returns>
public SqlParameter MakeOutParam(string ParamName, SqlDbType DbType, int Size)
{
return MakeParam(ParamName, DbType, Size, ParameterDirection.Output, null);
}
/// <summary>
/// 創(chuàng)建存儲過程參數(shù)
/// </summary>
/// <param name="ParamName">參數(shù)名</param>
/// <param name="DbType">參數(shù)類型</param>
/// <param name="Size">參數(shù)大小</param>
/// <param name="Direction">參數(shù)的方向(輸入/輸出)</param>
/// <param name="Value">參數(shù)值</param>
/// <returns>新參數(shù)對象</returns>
public SqlParameter MakeParam(string ParamName, SqlDbType DbType, Int32 Size, ParameterDirection Direction, object Value)
{
SqlParameter param;
if (Size > 0)
{
param = new SqlParameter(ParamName, DbType, Size);
}
else
{
param = new SqlParameter(ParamName, DbType);
}
param.Direction = Direction;
if (!(Direction == ParameterDirection.Output && Value == null))
{
param.Value = Value;
}
return param;
}
#endregion
#region 數(shù)據(jù)庫連接和關(guān)閉
/// <summary>
/// 打開連接池
/// </summary>
private void Open()
{
// 打開連接池
if (con == null)
{
//這里不僅需要using System.Configuration;還要在引用目錄里添加
con = new SqlConnection(GetSqlConnection());
con.Open();
}
}
/// <summary>
/// 關(guān)閉連接池
/// </summary>
public void Close()
{
if (con != null)
con.Close();
}
/// <summary>
/// 釋放連接池
/// </summary>
public void Dispose()
{
// 確定連接已關(guān)閉
if (con != null)
{
con.Dispose();
con = null;
}
}
#endregion
}
}

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Collections;
using HelloWinForm.DBUtility;
namespace HelloWinForm.DAL
{
class Student
{
public string test()
{
string str = "";
SqlDataReader dr = SQLHelper.ExecuteReader("select * from Student");
while (dr.Read())
{
str += dr["StudentNO"].ToString();
}
dr.Close();
return str;
}
}
}