Question

I am using SQL Server 2008 R2 Standard and I still very new to SQL Server.

I am trying to find when a x (measurement) has trend data that flatlines for longer than 48 intervals of the date time.

Thanks in advance.

My base query structure is

SELECT sites.site_name, 
       measurements.measurement_name, 
       trend_data_temp.trend_data_avg, 
       trend_data_temp.trend_data_time 
FROM   sites 
       INNER JOIN group_sites 
               ON sites.site_id = group_sites.site_id 
       INNER JOIN groups 
               ON group_sites.group_id = groups.group_id 
       INNER JOIN measurements 
               ON sites.site_id = measurements.site_id 
       INNER JOIN trend_data 
               ON measurements.measurement_id = trend_data.measurement_id 
       INNER JOIN trend_data_temp 
               ON measurements.measurement_id = trend_data_temp.measurement_id 
GROUP  BY sites.site_name, 
          measurements.measurement_name, 
          trend_data_temp.trend_data_avg, 
          trend_data_temp.trend_data_time 
ORDER  BY sites.site_name, 
          measurements.measurement_name 

Answer 1

slightly in the dark without any outlines of input data and output data but maybe you need something like this (not tested)

   SELECT 
           sites.site_name, 
           measurements.measurement_name, 
           trend_data_temp.trend_data_avg, 
           [occurances] = count(trend_data_temp.trend_data_time) 
    FROM   sites 
           INNER JOIN group_sites 
                   ON sites.site_id = group_sites.site_id 
           INNER JOIN groups 
                   ON group_sites.group_id = groups.group_id 
           INNER JOIN measurements 
                   ON sites.site_id = measurements.site_id 
           INNER JOIN trend_data 
                   ON measurements.measurement_id = trend_data.measurement_id 
           INNER JOIN trend_data_temp 
                   ON measurements.measurement_id = trend_data_temp.measurement_id 
    GROUP  BY 
           sites.site_name, 
           measurements.measurement_name, 
           trend_data_temp.trend_data_avg
    HAVING count(trend_data_temp.trend_data_time) >=48