datamanager.cs

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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;

/// <summary>
/// DataManager 数据管理中心
/// </summary>
public static class DataManager
{
    /// <summary>
    /// 数据库
    /// </summary>
    public static DataBase database;

    /// <summary>
    /// 初始化数据库
    /// </summary>
    public static void Start()
    {
        if (database != null)
            database.Dispose();
        database = new DataBase();
    }

    /// <summary>
    /// 清除数据库
    /// </summary>
    public static void End()
    {
        database.Dispose();
        System.Web.HttpContext.Current.Application.Clear();
    }

    /// <summary>
    /// 添加记录到某表，返回记录号ID。
    /// </summary>
    /// <param name="tablename">表名</param>
    /// <param name="row">输入的记录row</param>
    /// <returns>返回</returns>
    public static string Add(string tablename, DataRow row)
    {
        database.Tables[tablename].Rows.Add(row);
        return row["ID"].ToString();
    }

    /// <summary>
    /// 删除某表的指定某ID的记录，返回是否成功。
    /// </summary>
    /// <param name="tablename">表名</param>
    /// <param name="id">记录ID</param>
    /// <returns>是否成功</returns>
    public static bool Del(string tablename, string id)
    {
        DataRow row = database.Tables[tablename].Select("ID = " + id + "")[0];
        if (row != null)
        {
            row.Delete();
            return true;
        }
        else
        {
            return false;
        }
    }

    /// <summary>
    /// 修改某表的某记录某列，返回是否成功。
    /// </summary>
    /// <param name="tablename">表名</param>
    /// <param name="filterstr">选择条件</param>
    /// <param name="columnname">列名</param>
    /// <param name="columnvalue">修改值</param>
    /// <returns>是否成功</returns>
    public static bool Replace(string tablename, string filterstr, string columnname, object columnvalue)
    {
        DataRow row = database.Tables[tablename].Select(filterstr)[0];
        if (row != null)
        {
            row[columnname] = columnvalue;
            return true;
        }
        else
        {
            return false;
        }
    }

    /// <summary>
    /// 查询某表某Name记录的ID，返回ID查不到则返回string.Empty。
    /// </summary>
    /// <param name="tablename">表名</param>
    /// <param name="name">查询Name的值</param>
    /// <returns>ID的值</returns>
    public static string CallID(string tablename, string name)
    {
        DataRow[] row = database.Tables[tablename].Select("Name = '" + name+"'");
        if (row.Length == 0)
            return string.Empty;
        return row[0]["ID"].ToString();
    }

    /// <summary>
    /// 查询某表某ID记录的Name，返回Name。
    /// </summary>
    /// <param name="tablename">表名</param>
    /// <param name="id">查询ID的值</param>
    /// <returns>Name的值</returns>
    public static string CallName(string tablename, string id)
    {
        DataRow[] row = database.Tables[tablename].Select("ID = '" + id + "'");
        if (row.Length == 0)
            return string.Empty;
        return row[0]["Name"].ToString();
    }

    /// <summary>
    /// 按选择条件查询某表某记录，返回记录组。
    /// </summary>
    /// <param name="tablename">表名</param>
    /// <param name="filterstr">选择条件</param>
    /// <returns>返回记录组</returns>
    public static DataRow[] FindRow(string tablename, string filterstr)
    {
        DataRow[] row = database.Tables[tablename].Select(filterstr);
        return row;
    }

    /// <summary>
    /// 根据ID取任意列的值，返回string
    /// </summary>
    /// <param name="tablename">表名</param>
    /// <param name="columnname">要查询的列名</param>
    /// <param name="ID">查询ID</param>
    /// <returns>值</returns>
    public static string CallColumn(string tablename, string columnname, string ID)
    {
        DataRow[] row = database.Tables[tablename].Select("ID = " + ID );
        if (row.Length == 0)
            return string.Empty;
        return row[0][columnname].ToString();
    }
}