带有 sql 查询动态参数的 dapper

Question

在我的 asp.net web-api中，我从下面的代码片段中收到错误为"ORA-00936：缺少表达式"。我尝试了许多解决方案，但没有克服这个错误。我还想知道如何动态绑定多个参数。我正在使用oracle作为我的后端，并使用dapper作为我的ORM。

        string empId = json.EMPID; //'15RD005'
        var sql = @"Select id_no,SNO,REASON,APPLIEDDATE,Case
                    when LEAVE_TYPE = 0 then 'CL'
                    when LEAVE_TYPE = 1 then 'EL'
                    when LEAVE_TYPE = 2 then 'SL'
                    when LEAVE_TYPE = 3 then 'OFF'
                    when LEAVE_TYPE = 4 then 'OD-OFF'
                    when LEAVE_TYPE = 5 then 'LOP'
                    when LEAVE_TYPE = 6 then 'OPTIONAL' end LEAVE_TYPE,
                to_char(fromdate,'DD-MON-YYYY') f_date, to_char(todate,'DD-MON-YYYY') t_date,
                    Case when fromslot=0 then 'First-Half' when fromslot=1 then 'Second-Half' when fromslot=2 then 'Full-Day' end From_Slot,
                    Case when toslot=0 then 'First-Half' when toslot=1 then 'Second-Half' when toslot=2 then 'Full-Day' end To_Slot,
                applieddays APP_DAYS,
                    case when actinact=0 and cancel_idno is not null then 'Cancelled'
                    when actinact=1 and AUTH_IDNO   is null then 'Pending'
                    when actinact=0 and cancel_idno is not null then 'Rejected'
                    else 'Authorised' end leave_Status
                from Tleaves where to_char(Todate,'mm-yyyy') >= to_char(sysdate-30,'mm-yyyy') and to_char(todate,'mm-yyyy') <=to_char(sysdate,'mm-yyyy')
                 and to_char(Todate,'yyyy')=to_char(sysdate,'yyyy') and id_no like @EmpId Order by sno";

        try
        {
            using (OracleConnection db = new OracleConnection(conString))
            {
                db.Open();
                var pastLeavesReport = new PastLeavesReportDTO();
                //3.Present and last month lev status report
                List<PastLeavesReportInfoDTO> pastLeavesReportInfo = db.Query<PastLeavesReportInfoDTO>(sql, new { EmpId = empId }).ToList();
                pastLeavesReport.EMPID = "";
                pastLeavesReport.LEAVES = pastLeavesReportInfo;

                return Ok(
                 new EmpLeavesActionResponse(ActionStatusCodes.PastLeavesReportDataFound,
                               "",
                               pastLeavesReport));

            }
        }
        catch (Exception exp)
        {
            return Ok(
                 new EmpLeavesActionResponse(ActionStatusCodes.ServerException,
                               exp.Message,
                               null));
        }

Answer 1

最后，我解决了我的问题，而代码几乎没有变化。也就是说@Empid被更改为：Empid，因为oracle数据库以这种方式支持动态参数。对于我的第二个问题，即如何处理多个动态参数，我正在使用dappers DynamicParameters类，如下所示，

        var parameters = new Dictionary<string, object>();
        parameters.Add("ID", empId);
        DynamicParameters dbParams = new DynamicParameters();
        dbParams.AddDynamicParams(parameters);

我们可以在 dapper 中使用它，如下面的代码片段所示，参数查询是一个示例 sql 查询。

          dynamic result = db.Query(query, dbParams);

Answer 2

所以你在这里有一个逻辑问题，这可能是错误

case 
  when actinact=0 and cancel_idno is not null then 'Cancelled'
  when actinact=1 and AUTH_IDNO   is null then 'Pending'
  when actinact=0 and cancel_idno is not null then 'Rejected'
  else 'Authorised' 
end leave_Status

因为 actinact=0 并且 cancel_idno 不为 null 被列出两次

注意：当代码格式良好时，这很容易发现。

---

你说你想要两个参数，然后在新对象中添加

new { EmpId = empId }

成为

new { EmpId = empId,
      newparam = newvalue })

，然后在查询中使用@newparam。

文档 -> https://msdn.microsoft.com/en-us/library/bb397696.aspx