Linq to SQL

[Satish_S]

using (apReportDataContext context = new apReportDataContext())
{
var appointments = (
from app in context.t_msts
join li in context.Lead_In
on app.apm_LeadID equals li.iLeadID into app_li
from li in app_li.DefaultIfEmpty()
join cs in context.custContactInfos on li.iLeadID equals cs.id into li_cs
from cs in li_cs.DefaultIfEmpty()
join apm in context.atm_appointment_type_masts on app.apm_type_id equals apm.atm_id into cs_apm
from apm in cs_apm.DefaultIfEmpty()

                        select new
                        {
                          app.apm\_id,
                          app.apm\_name,
                          app.apm\_desc,
                          app.apm\_start\_time,
                          cs.CustomerName,
                          apm.atm\_type\_name,
                          
                        });

          




            grv.DataSource = appointments.Distinct();
            grv.DataBind();

        }

this is generating me result as expected now i need to pass paameters to this when generate report button is clicked, i have a drop down and if drop down value !=0 then i have to pass the value of it and if another text box field is filled then i have to pass that also as a parameter how can i do this?

[dan sh]

You need to use where keyword here. It behaves same as the where clause in the SQL statements. Something like this:

from element in someIEnumerable
where element.property == someValue
select element

[Satish_S]

thanks for your reply yes what you said is working but if suppose user not entering value of text box then the value will be empty, this will give error, i need to check as this for 5 input controls, and if a control value is not empty then i have to pass that one as a parameter. how to do this.

[dan sh]

If those values are mandatory, use RequiredFieldValidator. If not, then you will have to check for the null values. Since I do not know the exact scenario in your application, cannot provide any better solution.

[Satish_S]

Thanks again for your reply .. finally i got a solution and i have done it as below.

using (apReportDataContext context = new apReportDataContext())
{
var appointments = (
from app in context.t_msts
join li in context.Lead_In on app.apm_LeadID equals li.iLeadID into app_li
from li in app_li.DefaultIfEmpty()
join cs in context.custContactInfos on li.iLeadID equals cs.id into li_cs
from cs in li_cs.DefaultIfEmpty()
join apm in context.atm_appointment_type_masts on app.apm_type_id equals apm.atm_id into cs_apm
from apm in cs_apm.DefaultIfEmpty()
select new
{
app.apm_id,
app.apm_name,
app.apm_desc,
app.apm_start_time,
cs.CustomerName,
apm.atm_type_name
}
);

**

if (dropdown.SelectedIndex != 0) appointments=
apps.Where(ap => ap.apm_ID.Equals(dropdown.SelectedValue));

**grv.DataSource = appointments.Distinct(); grv.DataBind();