类别操作.类

namespace dal
{
    public class olecado
    {
        private olehelp olehelper;

        public olecado()
        {
            olehelper = new olehelp();

        }
        /// <summary>
        /// 选出所有
        /// </summary>
        /// <returns>数据表</returns>
        public DataTable selectall()
        {
            return olehelper.execquery("select * from category", CommandType.Text);

        }
        /// <summary>
        /// 根据id选择
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        public DataTable selectbyid(string id)
        {
            OleDbParameter[] paras = new OleDbParameter[] { new OleDbParameter("@id", id) };
            return olehelper.execquery("select * from category where id=@id", paras, CommandType.Text);
        }
        /// <summary>
        /// 根据内容选择
        /// </summary>
        /// <param name="catename"></param>
        /// <returns></returns>
        public DataTable selectbycatename(string catename)
        {
            OleDbParameter[] paras = new OleDbParameter[] { new OleDbParameter("@catename", catename) };
            return olehelper.execquery("select * from category where catename like '%'+@catename+'%'", paras, CommandType.Text);
        }
        /// <summary>
        /// 增加
        /// </summary>
        /// <param name="catename">名称</param>
        /// <returns>逻辑</returns>
        public bool insertcategory(string catename)
        {
            bool flag = false;
            string cmdtext = "insert into category(catename) values(@catename)";
            OleDbParameter[] paras = new OleDbParameter[] { new OleDbParameter("@catename", catename) };
            int res = olehelper.execnonquery(cmdtext, paras, CommandType.Text);
            if (res > 0)
            {
                flag = true;
            }
            return flag;
        }
        /// <summary>
        /// 删除
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        public bool deletecategory(string id)
        {
            bool flag = false;
            string cmdtext = "delete from category where id=@id";
            OleDbParameter[] paras = new OleDbParameter[] { new OleDbParameter("@id", id) };
            int res = olehelper.execnonquery(cmdtext, paras, CommandType.Text);
            if (res > 0)
            {
                flag = true;
            }
            return flag;
        }
        /// <summary>
        /// 根据id更新
        /// </summary>
        /// <param name="id"></param>
        /// <param name="catename"></param>
        /// <returns></returns>
        public bool fixcategory(string catename, string id)
        {
            bool flag = false;
            string cmdtext = "update category set catename=@catename where id=@id";
            OleDbParameter[] paras = new OleDbParameter[] { new OleDbParameter("@catename", catename), new OleDbParameter("@id", id) };
            int res = olehelper.execnonquery(cmdtext, paras, CommandType.Text);
            if (res > 0)
            {
                flag = true;
            }
            return flag;
        }
        /// <summary>
        /// 判断是否存在
        /// </summary>
        /// <param name="catename"></param>
        /// <returns></returns>
        public bool exist(string catename)
        {
            bool flag = false;
            OleDbParameter[] paras = new OleDbParameter[] { new OleDbParameter("@catename", catename) };
            DataTable dt = olehelper.execquery("select * from category where catename=@catename", paras, CommandType.Text);
            //DataTable dt = olehelper.execquery("select * from category where catename='" + catename + "'", CommandType.Text);
            if (dt.Rows.Count > 0)
            {
                flag = true;
            }
            return flag;
        }

    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.OleDb;
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原文地址:https://www.cnblogs.com/houweidong/p/2921291.html