asp.net sql or collection problem - asp.net

Question

following is the code on Placementsearch.aspx.cs
protected void Ok_Click(object sender, EventArgs e)
{
try
{
if (Page.IsValid)
{
int course_id = Convert.ToInt32(course.SelectedValue);
int passoutYear = Convert.ToInt32(passout.SelectedValue);
int currentBacklog = Convert.ToInt32(currrentBacklogDDL.SelectedValue);
int sex = Convert.ToInt32(gender.SelectedValue);
int? eGap = null;
int? firstYrPercent = null;
int? secondYrPercent = null;
int? thirdYrPercent = null;
int? finalYearpercent = null;
int? currentDegeePercentage = null;
int? highSchoolPercentge = null;
int? higherSchoolPercentage = null;
int? grauationPercentage = null;
int? diplomaPercentage = null;
int? noOfAtkt = null;
DateTime? date = null;
if (!string.IsNullOrEmpty(DOB.Text.Trim()))
{
string dateOfBirth = DOB.Text.Trim();
DateTime birthDate = DateTime.ParseExact(dateOfBirth, "dd/mm/yyyy", System.Globalization.CultureInfo.InvariantCulture);
string outPut = birthDate.ToString("mm/dd/YYYY");
date = Convert.ToDateTime(outPut);
}
if (!String.IsNullOrEmpty(educationGap.Text.Trim()))
{
eGap = Convert.ToInt32(educationGap.Text.Trim());
}
if (!string.IsNullOrEmpty(firstYear.Text))
{
firstYrPercent = Convert.ToInt32(firstYear.Text.Trim());
}
if (!string.IsNullOrEmpty(secondYear.Text.Trim()))
{
secondYrPercent = Convert.ToInt32(secondYear.Text.Trim());
}
if (!string.IsNullOrEmpty(thirdYear.Text))
{
thirdYrPercent = Convert.ToInt32(thirdYear.Text.Trim());
}
if (!string.IsNullOrEmpty(finalyear.Text.Trim()))
{
finalYearpercent = Convert.ToInt32(finalyear.Text.Trim());
}
if (!string.IsNullOrEmpty(currentDegree.Text.Trim()))
{
currentDegeePercentage = Convert.ToInt32(currentDegree.Text.Trim());
}
if (!string.IsNullOrEmpty(higherSchool.Text.Trim()))
{
higherSchoolPercentage = Convert.ToInt32(higherSchool.Text.Trim());
}
if (!string.IsNullOrEmpty(highSchool.Text.Trim()))
{
highSchoolPercentge = Convert.ToInt32(highSchool.Text.Trim());
}
if (!string.IsNullOrEmpty(graduation.Text.Trim()))
{
grauationPercentage = Convert.ToInt32(graduation.Text.Trim());
}
if (!string.IsNullOrEmpty(diploma.Text.Trim()))
{
diplomaPercentage = Convert.ToInt32(diploma.Text.Trim());
}
if (!string.IsNullOrEmpty(atkt.Text.Trim()))
{
noOfAtkt = Convert.ToInt32(atkt.Text.Trim());
}
Dictionary<string, object> paramList = new Dictionary<string, object>();
paramList.Add("#courseId", course_id);
paramList.Add("#passoutYear", passoutYear);
paramList.Add("#currentBacklog", currentBacklog);
paramList.Add("#sex", sex);
paramList.Add("#eGap", eGap);
paramList.Add("#firstYrPercent", firstYrPercent);
paramList.Add("#secondYrPercent", secondYrPercent);
paramList.Add("#thirdYrPercent", thirdYrPercent);
paramList.Add("#finalYearpercent", finalYearpercent);
paramList.Add("#currentDegeePercentage", currentDegeePercentage);
paramList.Add("#highSchoolPercentge", highSchoolPercentge);
paramList.Add("#higherSchoolPercentage", higherSchoolPercentage);
paramList.Add("#grauationPercentage", grauationPercentage);
paramList.Add("#diplomaPercentage", diplomaPercentage);
paramList.Add("#noOfAtkt", noOfAtkt);
paramList.Add("#date", date);
StringBuilder branchId= new StringBuilder();
foreach (ListItem li in branch.Items)
{
if (li.Selected)
{
branchId.Append(Convert.ToInt32(li.Value));
}
}
DataTable dt = searchManager.GetEligibleStudent(paramList, branchId);
}
}
catch (Exception ex)
{
COMMON.logger.Error("Error On Button click Ok", ex);
}
this is the method which is called from above page. this method is on class searchstudentDAO.cs
public DataTable GetEligibleStudent(Dictionary<string, object> paramList, StringBuilder branchId)
{
try
{
string cmd = #"SELECT * FROM [tbl_students] WHERE course_id=#courseId
AND branch_id IN(" + branchId + #")
AND (#firstYrPercent is null OR first_year_percent>=#firstYrPercent)
AND (#secondYrpercent is null OR second_year_percent>=#secondYrPercent)
AND (#thirdYrPercent is null OR third_year_percent>=#thirdYrPercent)
AND (#finalYearpercent is null OR final_year_percent>=#finalYearpercent)
AND (#currentDegeePercentage is null OR current_degree_percent>=#currentDegeePercentage)
AND (#passoutYear is null OR passing_year>=#passoutYear)
AND (#currentBacklog is null OR current_backlog<=#currentBacklog)
AND gender=#sex
AND (#eGap is null OR gapin_education<=#eGap)
AND (#highSchoolPercentge is null OR highschool_percentage>=#highSchoolPercentge)
AND (#higherSchoolPercentage is null OR ssc_percentage>=#higherSchoolPercentage)
AND (#grauationPercentage is null OR graduation_percentage>=#grauationPercentage)
AND (#diplomaPercentage is null OR diploma_percentage>=#diplomaPercentage)
AND (#noOfAtkt is null OR number_of_ATKT<=#noOfAtkt)
AND (#date is null OR DOB>=#date)";
//string cmd = "SELECT * FROM [tbl_branch] WHERE course_id IN(" + sb + ")";
if (dbManager.OpenConnection())
{
dt = dbManager.GetDataTable(cmd, paramList);
return dt;
}
else
{
dt = null;
return dt;
}
}
catch (Exception ex)
{
COMMON.logger.Error("Error ON Method Getting Eligible Students:SearchStudentDAO", ex);
dt = null;
return dt;
throw;
}
finally
{
dbManager.CloseConnection();
}
}
And followin is code called from the above method on paage App_Code/DBManager.cs
public DataTable GetDataTable(string strCmd, Dictionary<string, object> paramList)
{
try
{
DataTable dt = new DataTable();
SqlCommand cmd = new SqlCommand(strCmd, _sqlCon);
foreach (KeyValuePair<string, object> kvp in paramList)
{
cmd.Parameters.AddWithValue(kvp.Key, kvp.Value);
}
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(dt);
return dt;
}
catch (Exception ex)
{
logger.Error("Error when executing Query " + strCmd, ex);
throw;
return null;
}
}
Now i am getting exception for those null parameter which are not provided
"Parameterized Query '(#courseId int,#passoutYear int,#currentBacklog int,#sex int,#eG' expects parameter #finalYearpercent, which was not supplied."
please correct me where i am wrong

Answer 1

Instead of simply not adding those parameters if they're null, you need to add them, but with the "value" set to DBNull.Value.