类库中访问access数据库

Question

我想在类库写一段代码用来访问ACCESS数据库,方面其它页面的调用,请大家指点.

Answer 1

SQL简单版:
public class DataBase 
{
public static int IconIndex =0; 
// 连接数据源
public System.Data.SqlClient.SqlConnection con=null;
    /// <summary>
/// 创建一个SqlCommand对象以此来执行无参数的存储过程
/// </summary>
/// <returns>返回SqlCommand对象</returns>
public SqlDataAdapter CreateCommand(string procName) 
{
// 确认打开连接
Open(); System.Data.SqlClient.SqlDataAdapter Adp=new SqlDataAdapter(procName,con); return Adp;
}
/// <summary>
///执行无参数的存储过程
/// </summary>
public System.Data.SqlClient.SqlCommand Command(string ProcName)              
{
Open(); System.Data.SqlClient.SqlCommand com=new SqlCommand(ProcName,con); return com;
} /// <summary>
///执行需要单个参数的存储过程
/// </summary>
public System.Data.SqlClient.SqlCommand Command(System.Data.SqlClient.SqlParameter Para,string ProcName)  
{
Open();
System.Data.SqlClient.SqlCommand com=new SqlCommand();
com.Parameters.Add(Para);
com.CommandType=CommandType.StoredProcedure;
com.Connection=con;
com.CommandText=ProcName; return com; }
/// <summary>
/// 打开数据库连接.
/// </summary>
public void Open() 
{
// 打开数据库连接
if (con == null) 
{
con = new SqlConnection(ConfigurationSettings.AppSettings["Connection_str"]);
}
if(con.State == System.Data.ConnectionState.Closed)
{
con.Open();
}
} /// <summary>
/// 关闭数据库连接
/// </summary>
public void Close() 
{
if (con != null)
{
con.Close();
}
} /// <summary>
/// 释放资源,同时Close()
/// </summary>
public void Dispose() 
{
// 确认连接是否已经关闭
if (con != null) 
{
con.Dispose();     //Calling Dispose also calls SqlConnection.Close
con = null;
}
}
}

Answer 2

entlib的daab可以实现,当然自己写也是一个好的尝试

Answer 3

string conStr = ConfigurationSettings.AppSettings["ConnectionStr"]

Answer 4

我要访问ACCESS的类库.不是SQL的,SQL的我会,呵呵.

Answer 5

我要访问ACCESS的类库.不是SQL的,SQL的我会,呵呵.------------
一样，将相关的类，换成 OleDb如，public void ReadMyData(string connectionString)
{
    string queryString = "SELECT OrderID, CustomerID FROM Orders";
    using (OleDbConnection connection = new OleDbConnection(connectionString))
    {
        OleDbCommand command = new OleDbCommand(queryString, connection);
        connection.Open();
        OleDbDataReader reader = command.ExecuteReader();        while (reader.Read())
        {
            Console.WriteLine(reader.GetInt32(0) + ", " + reader.GetString(1));
        }
        // always call Close when done reading.
        reader.Close();
    }

Answer 6

public OleDbDataReader GetDataReaderMDB(string selectCmd) // Select From Table
        {
            
            string m_dbConnection  ="Provider=Microsoft.Jet.OLEDB.4.0;Data Source="+HttpContext.Current.Request.PhysicalApplicationPath+System.Configuration.ConfigurationSettings.AppSettings["PATH"];
            if (m_dbConnection==null) throw new Exception("Error-> DSN not set in Config.web");            OleDbConnection m_SqlConnection = new OleDbConnection(m_dbConnection);
            OleDbCommand    m_SqlCommand    = new OleDbCommand(selectCmd, m_SqlConnection);
            try 
            {
                m_SqlCommand.Connection.Open();
            } // end try
            catch (Exception e)
            {
                throw new Exception("Error in CInfo:GetDataReader()-> " + e.ToString());
            }
            return m_SqlCommand.ExecuteReader(CommandBehavior.CloseConnection); 
        } // end Select 
web.config<add key="PATH" value="bbs/mdb/dxxobbs.mdb" />

Answer 7

直接拿来就可以用了,上回做东西的时候改的,还加了一个防注入的.using System;
using System.Data;
using System.Data.SqlClient; 
using System.Data.OleDb;
using System.Web;
namespace cjyy
{
/// <summary>
/// DataAccess 的摘要说明。
/// <description>数据处理基类,调用方式：DataAccess.DataSet((string)sqlstr);或者DataAccess.DataSet((string)sqlstr,ref DataSet ds); </description>
/// </summary>
public class DataAccess
{
#region  属性
protected static OleDbConnection conn=new OleDbConnection();
protected static OleDbCommand    comm=new OleDbCommand(); protected static string connSting=connString.createConnString();//string.Format("Provider={0};Data Source={1}",System.Configuration.ConfigurationSettings.AppSettings["Provider"],System.Web.HttpContext.Current.Server.MapPath(System.Configuration.ConfigurationSettings.AppSettings["DataSource"]));
 
#endregion
public DataAccess()
{
//init();
}
#region 内部函数  静态方法中不会执行DataAccess()构造函数 /// <summary>
/// 打开数据库连接
/// </summary>
private static void openConnection()
{
if (conn.State == ConnectionState.Closed)
{
//SysConfig.ConnectionString 为系统配置类中连接字符串，如："server=localhost;database=databasename;uid=sa;pwd=;"
conn.ConnectionString =DataAccess.connSting;
comm.Connection =conn;
try
{
conn.Open();
}
catch(Exception e)
{
throw new Exception(e.Message);
}
}
}
/// <summary>
/// 关闭当前数据库连接
/// </summary>
private static void closeConnection()
{
if(conn.State == ConnectionState.Open)
    conn.Close();
conn.Dispose();
comm.Dispose();
}
#endregion
/// <summary>
/// 执行Sql查询语句
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
public static void ExecuteSql(string sqlstr)
{
try
{
openConnection();
comm.CommandType =CommandType.Text ;
comm.CommandText =sqlstr;
comm.ExecuteNonQuery(); 
}
catch(Exception e)
{
throw new Exception(e.Message);
}
finally
{
closeConnection();
}
} /// <summary>
/// 执行Sql查询语句并返回第一行的第一条记录,返回值为object 使用时需要拆箱操作 -> Unbox
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
/// <returns>object 返回值 </returns>
public static object ExecuteScalar(string sqlstr)
{
object obj=new object();
try
{
openConnection();
comm.CommandType =CommandType.Text ;
comm.CommandText =sqlstr;
obj=comm.ExecuteScalar(); 
}
catch(Exception e)
{
throw new Exception(e.Message);
}
finally
{
closeConnection();
}
return obj;
}
/// <summary>
/// 返回指定Sql语句的SqlDataReader，请注意，在使用后请关闭本对象，同时将自动调用closeConnection()来关闭数据库连接
/// 方法关闭数据库连接
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
/// <returns>SqlDataReader对象</returns>
public static OleDbDataReader dataReader(string sqlstr)
{
OleDbDataReader dr=null;
try
{
openConnection();
comm.CommandText =sqlstr;
comm.CommandType =CommandType.Text ;
dr=comm.ExecuteReader(CommandBehavior.CloseConnection); 
}
catch
{
try
{
dr.Close();
closeConnection();
}
catch
{
}
}
return dr;
} /// <summary>
/// 返回指定Sql语句的SqlDataReader，请注意，在使用后请关闭本对象，同时将自动调用closeConnection()来关闭数据库连接
/// 方法关闭数据库连接
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
/// <param name="dr">传入的ref DataReader 对象</param>
public static void dataReader(string sqlstr,ref OleDbDataReader dr)
{
try
{
openConnection();
comm.CommandText =sqlstr;
comm.CommandType =CommandType.Text ;
dr=comm.ExecuteReader(CommandBehavior.CloseConnection); 
}
catch
{
try
{
if(dr!=null && !dr.IsClosed)
dr.Close();
}
catch
{
}
finally
{
closeConnection();
}
}
finally
{
                closeConnection();
}
} /// <summary>
/// 返回指定Sql语句的DataSet
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
/// <returns>DataSet</returns>
public static DataSet dataSet(string sqlstr)
{
DataSet ds= new DataSet();
OleDbDataAdapter da=new OleDbDataAdapter();
try
{
openConnection();
comm.CommandType =CommandType.Text ;
comm.CommandText =sqlstr;
da.SelectCommand =comm;
da.Fill(ds);
}
catch(Exception e)
{
throw new Exception(e.Message); 
}
finally
{
closeConnection();
}
return ds;
} /// <summary>
/// 返回指定Sql语句的DataSet
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
/// <param name="ds">传入的引用DataSet对象</param>
public static void dataSet(string sqlstr,ref DataSet ds)
{
OleDbDataAdapter da=new OleDbDataAdapter();
try
{
openConnection();
comm.CommandType =CommandType.Text ;
comm.CommandText =sqlstr;
da.SelectCommand =comm;
da.Fill(ds);
}
catch(Exception e)
{
throw new Exception(e.Message); 
}
finally
{
closeConnection();
}
}
/// <summary>
/// 返回指定Sql语句的DataSet
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
/// <param name="startInt">查询的开始的</param>
/// <param name="maxInt">查询终止的</param>
/// <param name="tableName">表名</param>
public static DataSet dataSet(string sqlstr,int startInt,int maxInt,string tableName)
{
DataSet ds= new DataSet();
OleDbDataAdapter da=new OleDbDataAdapter();

try
{
openConnection();
comm.CommandType =CommandType.Text ;
comm.CommandText =sqlstr;
da.SelectCommand =comm;
da.Fill(ds,startInt,maxInt,tableName);
}
catch(Exception e)
{
throw new Exception(e.Message); 
}
finally
{
closeConnection();
}
return ds;
}
/// <summary>
/// 返回指定Sql语句的DataTable
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
/// <returns>DataTable</returns>
public static DataTable dataTable(string sqlstr)
{
OleDbDataAdapter da=new OleDbDataAdapter();
DataTable datatable=new DataTable();
try
{
openConnection();
comm.CommandType =CommandType.Text ;
comm.CommandText =sqlstr;
da.SelectCommand =comm;
da.Fill(datatable);
}
catch(Exception e)
{
throw new Exception(e.Message); 
}
finally
{
closeConnection();
}
return datatable;
} /// <summary>
/// 执行指定Sql语句,同时给传入DataTable进行赋值 
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
/// <param name="dt">ref DataTable dt </param>
public static void dataTable(string sqlstr,ref DataTable dt)
{
OleDbDataAdapter da=new OleDbDataAdapter();
try
{
openConnection();
comm.CommandType =CommandType.Text ;
comm.CommandText =sqlstr;
da.SelectCommand =comm;
da.Fill(dt);
}
catch(Exception e)
{
throw new Exception(e.Message); 
}
finally
{
closeConnection();
}
} }}

Answer 8

呵呵.类库中没有WEB.CONFIG是不是要自己加一个啊!

Answer 9

把SqlCommand之类的换成OleDbCommand

Answer 10

把SqlCommand之类的换成OleDbCommand,能行的话我就不发这个高分的帖子了.呵呵.

Answer 11

是从我程序里 扣出来
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Text.RegularExpressions;
using System.Data.OleDb;/// <summary>
/// WebFunction 数据操作类
/// </summary>
public class WebFunction
{
    protected static OleDbConnection conn = new OleDbConnection();
    protected static OleDbCommand comm = new OleDbCommand();    public WebFunction()
    {
        //
        // TODO: 在此处添加构造函数逻辑
        //
    }    /// <summary> 
    /// 打开数据库连接 
    /// </summary> 
    private static void openConnection()
    {
        if (conn.State == ConnectionState.Closed)
        {
            conn.ConnectionString = System.Web.Configuration.WebConfigurationManager.ConnectionStrings["connStr"].ConnectionString;
            comm.Connection = conn;
            try
            {
                conn.Open();
            }
            catch (Exception e)
            {
                throw new Exception(e.Message);
            }
        }
    }    /// <summary> 
    /// 关闭当前数据库连接 
    /// </summary> 
    private static void closeConnection()
    {
        if (conn.State == ConnectionState.Open)
            conn.Close();
        conn.Dispose();
        comm.Dispose();
    }
    /// <summary> 
    /// 执行Sql查询语句 
    /// </summary> 
    /// <param name="sqlstr">传入的Sql语句</param> 
    public static void ExecuteSql(string sqlstr)
    {
        try
        {
            openConnection();
            comm.CommandType = CommandType.Text;
            comm.CommandText = sqlstr;
            comm.ExecuteNonQuery();
        }
        catch (Exception e)
        {
            throw new Exception(e.Message);
        }
        finally
        {
            closeConnection();
        }
    }    /// <summary> 
    /// 执行Sql更新语句 
    /// </summary> 
    /// <param name="sqlstr">传入的Sql语句</param>
    /// <returns>布尔值</returns>
    public static bool ExecuteUpdate(string sqlstr)
    {
        int isUpdateOk = 0;
        try
        {
            openConnection();
            comm.CommandType = CommandType.Text;
            comm.CommandText = sqlstr;
            isUpdateOk = Convert.ToInt32(comm.ExecuteNonQuery());
        }
        catch (Exception e)
        {
            throw new Exception(e.Message);
        }
        finally
        {
            closeConnection();
        }
        if (isUpdateOk > 0)
        {
            return true;
        }
        else
        {
            return false;
        }
    }    /// <summary> 
    /// 执行Sql查询语句并返回第一行的第一条记录,返回值为object 使用时需要拆箱操作 -> Unbox 
    /// </summary> 
    /// <param name="sqlstr">传入的Sql语句</param> 
    /// <returns>object 返回值 </returns> 
    public static object ExecuteScalar(string sqlstr)
    {
        object obj = new object();
        try
        {
            openConnection();
            comm.CommandType = CommandType.Text;
            comm.CommandText = sqlstr;
            obj = comm.ExecuteScalar();
        }
        catch (Exception e)
        {
            throw new Exception(e.Message);
        }
        finally
        {
            closeConnection();
        }
        return obj;
    }    /// <summary> 
    /// 返回指定Sql语句的SqlDataReader，请注意，在使用后请关闭本对象，同时将自动调用closeConnection()来关闭数据库连接 
    /// 方法关闭数据库连接 
    /// </summary> 
    /// <param name="sqlstr">传入的Sql语句</param> 
    /// <returns>SqlDataReader对象</returns> 
    public static OleDbDataReader dataReader(string sqlstr)
    {
        OleDbDataReader dr = null;
        try
        {
            openConnection();
            comm.CommandText = sqlstr;
            comm.CommandType = CommandType.Text;
            dr = comm.ExecuteReader(CommandBehavior.CloseConnection);
        }
        catch
        {
            try
            {
                dr.Close();
                closeConnection();
            }
            catch
            {
            }
        }
        return dr;
    }    ///<summary>
    ///关闭datareader
    ///传入SqlDataReader的ref
    ///</summary>
    public static void closeDataReader(ref OleDbDataReader sdr)
    {
        try
        {
            sdr.Close();
            sdr.Dispose();
        }
        catch (Exception)
        { }
    }    /// <summary> 
    /// 返回指定Sql语句的DataSet 
    /// </summary> 
    /// <param name="sqlstr">传入的Sql语句</param> 
    /// <returns>DataSet</returns> 
    public static DataSet dataSet(string sqlstr)
    {
        DataSet ds = new DataSet();
        OleDbDataAdapter da = new OleDbDataAdapter();
        try
        {
            openConnection();
            comm.CommandType = CommandType.Text;
            comm.CommandText = sqlstr;
            da.SelectCommand = comm;
            da.Fill(ds);
        }
        catch (Exception e)
        {
            throw new Exception(e.Message);
        }
        finally
        {
            closeConnection();
        }
        return ds;
    }    /// <summary> 
    /// 返回指定Sql语句的DataSet 
    /// </summary> 
    /// <param name="sqlstr">传入的Sql语句</param> 
    /// <param name="ds">传入的引用DataSet对象</param> 
    public static void dataSet(string sqlstr, ref DataSet ds)
    {
        OleDbDataAdapter da = new OleDbDataAdapter();
        try
        {
            openConnection();
            comm.CommandType = CommandType.Text;
            comm.CommandText = sqlstr;
            da.SelectCommand = comm;
            da.Fill(ds);
        }
        catch (Exception e)
        {
            throw new Exception(e.Message);
        }        finally
        {
            closeConnection();
        }
    }
}

Answer 12

这个写在页面里是没有问题的.可是写在类库里面就找不到"System.Web.Web.Configuration"中的configuration了.并且类库中没有WEB.CONFIG.那又怎么办.还要手动一个吗?不太现实吧!呵呵.