Go doesn't have LINQ, but it does have a database/sql package. If you're not afraid of using strings, probably the cleanest way to do this would be to use sqlite, an embedded database, that understands SQL and has support for in-memory tables. Here's a go binding:
https://godoc.org/github.com/mattn/go-sqlite3 And an example: https://astaxie.gitbooks.io/build-web-application-with-golang/content/en/05.3.html You can use the special string: *:memory:* for an in-memory table rather than one stored on disk. If you're looking for something less generic, but still fairly clean, you can use a struct as a key in a hash table: https://play.golang.org/p/1CIpvWd0jZ type Key struct { id1, id2, id3 int // etc } type Record struct { Key money int } func main() { records := []Record{ {Key{1, 2, 3}, 1000}, {Key{1, 2, 3}, 500}, {Key{1, 2, 3}, 100}, } m := map[Key]int{} for _, r := range records { m[r.Key] += r.money } fmt.Println(m) // map[{1 2 3}:1600] } On Tuesday, October 11, 2016 at 5:53:12 PM UTC-4, Marcos Bortolussi wrote: > > Hi, I come from the .NET world where I had LINQ so i could do in memory > queries like the one we usually see in SQL. > > I have a slice of this structure I want to group by 8 fields, and then sum > another integer field. Something like: > > type Register struct { > id1 int > id2 int > id3 int > id4 int > id5 int > id6 int > id7 int > id8 int > money int > } > > > I thought in: > > 1. Creating an Equal function, to compare structures (those eight > fields). > 2. Iterate over the collection I'm analyzing. > 1. For each item check if it is already in the hash table. > 2. If it is there => I sum the field. > 3. If it is not => I add the new item to hash table. > > Is there a better way or any beautiful, perforfomant and easy ready to use > library? > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
