Ureport is rarely used. At present, there are projects in the unit that happen to be used. There are also many pitfalls. It is slightly different from other reports. Record it here and arrange the pitfalls for everyone.
The current requirement is to require data to be displayed like this 
1. Create a data source
1.1 B2, C1, D2, C4, and C2 each use different data sets
B2 data set is mainly for displaying vehicle information
C1 data set is mainly for date display
D2 data set is mainly for summary statistics by vehicle
C4 data set is mainly for summary statistics by date
C2 is mainly for list information statistics
2. Cell settings
A2
B2
C1
C2 is mainly to match the filter conditions
C2 display needs to rely on vehicle and time matching, so we use group by in sql to filter out data, and then use filtering to match the displayed results with date and vehicle respectively. If there is blank data, it needs to use configuration conditions to determine the default value
D2
D2 displays the power information, which is to summarize the data of this line, query it through sql, and then filter and bind it through the vehicle and the car in B2
C4
C4 is the summary statistics of each day. Normally, it is enough to directly sum, but ureport shows that the result is a bit unsatisfactory. Some data sums are successful, but some list data are not summed. All the documents form a data set to match the time of C1. filter
D2
3. Results display
