Dapper with sql query dynamic parameters

Question

In my asp.net web-api, am getting error as "ORA-00936: missing expression" from below code snippet. I had tried many solutions but i did not overcome this error. And also i want to know how do i bind more than one parameter dynamically. I am using oracle as my back-end and dapper as my 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));

        }

Solution 1

Finally i solved my issue with little change in my code. That is @Empid is changed into :Empid, since oracle database supports dynamic parameters in this way. And for my second question that is how to handle with multiple dynamic parameters i am using dappers DynamicParameters class as shown below,

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

        DynamicParameters dbParams = new DynamicParameters();
        dbParams.AddDynamicParams(parameters);

And we can use this in dapper as shown in below code snippe, Parameter query is a sample sql query.

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

Solution 2

So you have a logic problem here which might be the error

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

because actinact=0 and cancel_idno is not null is listed twice

Note: This is easy to spot when the code is nicely formatted.

---

You say you want two parameters just add then in the new object

new { EmpId = empId }

becomes

new { EmpId = empId,
      newparam = newvalue })

and then use @newparam in your query.

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