asp.net中数据库连接类的写法？（多多益善，尽量全面）

做一个DBHelper类在，数据访问层中直接调用它

public class DBHelper

{

private static SqlConnection connection

public static SqlConnection Connection

{

get

{

string connectionString = "server=(local)\\db2005database=MyBookShopuid=sapwd=sasa"

//string connectionString = ConfigurationManager.ConnectionStrings["MyConstr"].ConnectionString

if (connection == null)

{

connection = new SqlConnection(connectionString)

connection.Open()

}

else if (connection.State == System.Data.ConnectionState.Closed)

{

connection.Open()

}

else if (connection.State == System.Data.ConnectionState.Broken)

{

connection.Close()

connection.Open()

}

return connection

}

}

public static int ExecuteCommand(string safeSql)

{

SqlCommand cmd = new SqlCommand(safeSql, Connection)

int result = cmd.ExecuteNonQuery()

return result

}

public static int GetScalar(string safeSql)

{

SqlCommand cmd = new SqlCommand(safeSql, Connection)

int result = Convert.ToInt32(cmd.ExecuteScalar())

return result

}

public static SqlDataReader GetReader(string safeSql)

{

SqlCommand cmd = new SqlCommand(safeSql, Connection)

SqlDataReader reader = cmd.ExecuteReader()

return reader

}

public static DataTable GetDataSet(string safeSql)

{

DataSet ds = new DataSet()

SqlCommand cmd = new SqlCommand(safeSql, Connection)

SqlDataAdapter da = new SqlDataAdapter(cmd)

da.Fill(ds)

return ds.Tables[0]

}

MySQLConnection conn = null

conn = new MySQLConnection(new MySQLConnectionString("IP", "库", "用户", "密码").AsString)

MySQLDataAdapter rs = new MySQLDataAdapter("select uid from pw_memberinfo", conn)

DataTable T = new DataTable()

rs.Fill(T)

DataTableReader dtr = T.CreateDataReader()

while (dtr.Read())

{

Console.WriteLine(dtr[0] + "###" + dtr.GetValue(1))

//输出的是第一列和第二列的值，这里是自动转化的不用写tostring()

}

---