如何计算当月的员工读数

Question

I'm trying to work out how to make this view for my database

The number of meters read in the current month by each of the meter readers (this view should be able to be used at any time without having to be changed to accommodate the date).

The main trouble I'm having is counting how many times the employee has read a meter in the month. I'm using oracle and sql developer.

These are my tables:

a2_METERREADER

 - EMPLOYEEID
 - FIRSTNAME
 - LASTNAME

a2_READING

 - READINGID
 - METERID
 - EMPLOYEEID
 - BILLNUMBER
 - READING
 - DATERECORD

a2_Watermeter

 - METERID
 - ADDRESS
 - SUBURB
 - POSTCODE
 - STATUS
 - CUSTOMERID
 - REPLACE
 - INSTALLDATE

Answer 1

You need to join the meter reader and reading tables and count the number of rows, grouped by employee for the month in question.

Something along these lines:

SELECT reader.EMPLOYEEID, COUNT(reading.READINGID)
FROM a2_METERREADER reader, a2_READING reading
WHERE reader.EMPLOYEEID = reading.EMPLOYEEID
AND YEAR(reading.DATERECORD) = YEAR(SYSDATE)
AND MONTH(reading.DATERECORD) = MONTH(SYSDATE)
GROUP BY reader.EMPLOYEEID

Answer 2

IF your daterecord is a DATE then to access current month from Windows you can do this.

SELECT EMPLOYEEID, COUNT(*)
FROM a2_READING
WHERE TO_CHAR(DATERECORD, 'MM/YYYY') = TO_CHAR(SYSDATE, 'MM/YYYY')
GROUP BY EMPLOYEEID

This way you eliminate the days from DATERECORD (only keeps months and year) and it has to be the same with the SYSDATE (Current Date) again converted to keep month and year.

You dont need to join with METERREADER table if you only need the IDs