获取一年中每个月的总金额

Question

SELECT 
SUM(CASE MONTH(str_to_date(sm.BillDate, '%d/%m/%Y')) WHEN 1 THEN sm.GrandTotal ELSE 0 END) AS 'January',
SUM(CASE MONTH(str_to_date(sm.BillDate, '%d/%m/%Y')) WHEN 2 THEN sm.GrandTotal ELSE 0 END) AS 'February',
SUM(CASE MONTH(str_to_date(sm.BillDate, '%d/%m/%Y')) WHEN 3 THEN sm.GrandTotal ELSE 0 END) AS 'March',
SUM(CASE MONTH(str_to_date(sm.BillDate, '%d/%m/%Y')) WHEN 4 THEN sm.GrandTotal ELSE 0 END) AS 'April',
SUM(CASE MONTH(str_to_date(sm.BillDate, '%d/%m/%Y')) WHEN 5 THEN sm.GrandTotal ELSE 0 END) AS 'May',
SUM(CASE MONTH(str_to_date(sm.BillDate, '%d/%m/%Y')) WHEN 6 THEN sm.GrandTotal ELSE 0 END) AS 'June',
SUM(CASE MONTH(str_to_date(sm.BillDate, '%d/%m/%Y')) WHEN 7 THEN sm.GrandTotal ELSE 0 END) AS 'July',
SUM(CASE MONTH(str_to_date(sm.BillDate, '%d/%m/%Y')) WHEN 8 THEN sm.GrandTotal ELSE 0 END) AS 'August',
SUM(CASE MONTH(str_to_date(sm.BillDate, '%d/%m/%Y')) WHEN 9 THEN sm.GrandTotal ELSE 0 END) AS 'September',
SUM(CASE MONTH(str_to_date(sm.BillDate, '%d/%m/%Y')) WHEN 10 THEN sm.GrandTotal ELSE 0 END) AS 'October',
SUM(CASE MONTH(str_to_date(sm.BillDate, '%d/%m/%Y')) WHEN 11 THEN sm.GrandTotal ELSE 0 END) AS 'November',
SUM(CASE MONTH(str_to_date(sm.BillDate, '%d/%m/%Y')) WHEN 12 THEN sm.GrandTotal ELSE 0 END) AS 'December'
FROM
  sales_master sm
WHERE
  YEAR(str_to_date(sm.BillDate, '%d/%m/%Y'))='2017'
GROUP BY 
  MONTH(str_to_date(sm.BillDate, '%d/%m/%Y'))

I am working with MySQL where I need the total Amount spend each month for a given year (If for a given month there is no amount spend then it should print Zero). The above query does exactly what I need but I get the total values in separate rows. I need something like for all the months all the value should come in one single row. So that I can read easily.

Answer 1

You are close. Just remove the GROUP BY .

You should not be storing dates as strings. On rare occasions, that is necessary. But I would advise you to fix the type format, so the date is stored as a date.

Second, you can simplify the logic using like . If you have strings, use string operations:

SELECT SUM(CASE WHEN sm.BillDate LIKE '%/01/%' THEN sm.GrandTotal ELSE 0 END) AS January,
       . . .

Third, YEAR() returns an integer, so the comparison should be to an integer. However, given that the value is a string, just do:

WHERE BillDate LIKE '%2017'

Or, as mentioned earlier, fix your data so you are storing dates using the proper data type.