sql - Query for each element -

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i given following database schema

donuts (name: string, price: integer)  grocery (no: string, gname: string, mincredit: integer)  distributor (dname: string, gno: string, purchaseyear: integer)

for each year (distributor.purchaseyear), grocery "vons" purchased atleast 1 donut, find number of donuts purchased. output set of tuples, indicates year , number of donuts purchased "vons"

i not sure how approach this. tried

 select (d.purchaseyear, count(dd.name))  distributor d, donut dd, grocery g  g.name = "vons"

this seems give me incorrect output.

assuming have schema below

donuts (gname: string, price: integer, purchaseyear: integer) // record every donut purchased grocery gname in year grocery (gno: string, gname: string, mincredit: integer)  // grocery details distributor (dname: string, gno: string, purchaseyear: integer) // distributor details

you can data below query

select          g.name       , d.purchaseyear       , count(do.gname) distributor d join grocery g on g.gno = d.gno join donuts on do.gname = g.gname g.name = 'vons' group g.name, d.purchaseyear

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