Show on a label a value regarding the current week

[#1]

Good afternoon , I have to make a report that shows on a label the sale of the current week and the other the sale of the previous week. But the week we use is not the same as Week, WeekName .. functions . I need something like this query .

Select semana_ano, sum(qtd) from tabela where semana_ano =  (select semana_ano from calendario where data = currentdate()).

Example:

WEEK_YEAR	DATE	SELL
16-32	01/08/2016	0
16-31	31/07/2016	1000
16-31	30/07/2016	500
16-31	29/07/2016	500
16-31	28/07/2016	600
16-31	27/07/2016	700
16-31	26/07/2016	100
16-31	25/07/2016	200
16-30	24/07/2016	300
16-30	23/07/2016	400
16-30	22/07/2016	500
16-30	21/07/2016	600
16-30	20/07/2016	400
16-30	19/07/2016	300
16-30	18/07/2016	400
16-30	17/07/2016	800

I need to create a label that has , for example.... IF TODAY IS 29/07, this label should add the SALES days 31,30,29,28,27,26,25 , ie all dates of the week 16-31 , which is the week regarding the day ( 29/07 ) .

In another label you must be the sale of the previous week , ie if today is 29/07 , week 16-31 , will show the sum of sales days regarding the week 16-30 ( last week )

Thanks a lot for the help.

Note: Title translated to English by Community Moderator as a courtesy.

[#2]

Isso ai!

Faça esse if em uma variável e use a variável no set analisys.

Por favor marque uma das respostas como correta se uma delas te atendeu para manter a comunidade organizada.