zoukankan      html  css  js  c++  java
  • SQL 多条件查询技巧

    #region 多条件搜索时,使用List集合来拼接条件(拼接Sql)


                StringBuilder sql = new StringBuilder("select * from PhoneNum");
                List<string> wheres = new List<string>();
                if (cboGroup.SelectedIndex != 0)
                {
                    wheres.Add(" ptypeid=" + cboGroup.Text.Split('|')[0]);
                }

                if (txtSearchName.Text.Trim().Length > 0)
                {
                     wheres.Add(" pname like '%" + txtSearchName.Text.Trim() + "%'");
                }

                if (txtSearchCellPhone.Text.Trim().Length > 0)
                {
                     wheres.Add(" pcellphone like '%" + txtSearchCellPhone.Text.Trim() + "%'");
                }


                //判断用户是否选择了条件
                if (wheres.Count > 0)
                {
                    string wh = string.Join(" and ", wheres.ToArray());
                    sql.Append(" where " + wh);
                }
                #endregion

                #region 多条件搜索使用带参数的sql语句

                StringBuilder sql = new StringBuilder("select * from PhoneNum");
                List<string> wheres = new List<string>();
                List<SqlParameter> listParameter = new List<SqlParameter>();

                if (cboGroup.SelectedIndex != 0)
                {
                    wheres.Add(" ptypeid=@typeid ");
                    listParameter.Add(new SqlParameter("@typeid", cboGroup.Text.Split('|')[0]));
                }

                if (txtSearchName.Text.Trim().Length > 0)
                {
                    wheres.Add(" pname like @pname ");
                    //pname like '%乔%'
                    //pname liek '%'+@pname+'%'
                    listParameter.Add(new SqlParameter("@pname", "%" + txtSearchName.Text.Trim() + "%"));
                }

                if (txtSearchCellPhone.Text.Trim().Length > 0)
                {
                    wheres.Add(" pcellphone like @cellphone ");
                    listParameter.Add(new SqlParameter("@cellphone", "%" + txtSearchCellPhone.Text.Trim() + "%"));
                }


                //判断用户是否选择了条件
                if (wheres.Count > 0)
                {
                    string wh = string.Join(" and ", wheres.ToArray());
                    sql.Append(" where " + wh);
                }

                SqlHelper.ExecuteDataTable(sql.ToString(), listParameter.ToArray());
                #endregion

  • 相关阅读:
    MySql插不进中文,以及IDEA连接MySql出现小段乱码问题
    安装Consul环境并启动
    格式化日期,首字母大写
    设计模式
    用户刷新页面,中止客户端面请求,怎么判断服务端也取消请求
    Token使用
    IdentityServer4搭建和使用
    Filter 过滤器
    添加Filter 并控制它的执行顺序
    在startup 添加数据库链接字符串
  • 原文地址:https://www.cnblogs.com/bo0214/p/12868909.html
Copyright © 2011-2022 走看看