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  • C# 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

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  • 原文地址:https://www.cnblogs.com/jiangyunfeng/p/11296240.html
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