ADO.NET DBHelper 类库

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Data.SqlClient;

using System.Data;

namespace ADO1

{

public class DBHelper

{

public static string Message = string.Empty;

static SqlConnection conn = null;

/// <summary>

/// 连接数据库

/// </summary>

private static void OpenConn()

{

conn = new SqlConnection("Data Source=.;Initial Catalog=MySchoolBase;Integrated Security=True");

conn.Open();

}

/// <summary>

/// 执行增删改操作

/// </summary>

/// <param name="sql">要执行的SQL语句</param>

/// <returns>返回成功所影响的行数</returns>

public static int ExecuteCommand(string sql)

{

int ok = 0;

try

{

OpenConn();

SqlCommand cmd = new SqlCommand(sql, conn);

ok = cmd.ExecuteNonQuery();

Close();

}

catch (Exception e)

{

ok = -1;

Message = e.Message;

}

return ok;

}

/// <summary>

/// 执行查询返回单行单列的数值形式

/// </summary>

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

/// <returns></returns>

public static int ExecuteScalar(string sql)

{

int ok = 0;

try

{

OpenConn();

SqlCommand cmd = new SqlCommand(sql,conn);

ok = Convert.ToInt32(cmd.ExecuteScalar());

Close();

}

catch (Exception e)

{

ok = -1;

Message = e.Message;

}

return ok;

}

public static DataTable GetDataTable(string sql)//使用Adapter对象连接数据库表(不传表名)

{

DataTable dt = new DataTable();

try

{

OpenConn();

SqlDataAdapter adapter = new SqlDataAdapter(sql, conn);

adapter.Fill(dt);

Close();

}

catch (Exception e)

{

Message = e.Message;

}

return dt;

}

public static DataTable GetDataTable(string sql, string tableName)//使用Adapter对象连接数据库表

{

DataTable dt = new DataTable(tableName);

try

{

OpenConn();

SqlDataAdapter adapter = new SqlDataAdapter(sql, conn);

adapter.Fill(dt);

Close();

}

catch (Exception e)

{

Message = e.Message;

}

return dt;

}

/// <summary>

/// 执行查询

/// </summary>

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

/// <returns></returns>

public static SqlDataReader ExecuteReader(string sql)

{

SqlDataReader rs = null;

try

{

OpenConn();

SqlCommand cmd = new SqlCommand(sql,conn);

rs = cmd.ExecuteReader();

}

catch (Exception e)

{

Message = e.Message;

}

return rs;

}

/// <summary>

/// 关闭数据库连接

/// </summary>

public static void Close()

{

if (conn != null)

{

conn.Close();

}

}

}

}