How to implement complex SQL functions about go-linq

[cleitonmarx]

Hey, @penhauer-xiao and @107295472! My apologies for the delay. Here's a possible code example for your problem:

        type TransactionRecord struct {
		ID        uint64
		AccountID string
		TCode     string
		TDate     string
		TType     uint8
		Amount    float64
	}

	type GroupedRecord struct {
		AccountID string
		TCode     string
		TDate     string
		TType     uint8
		SumAmount float64
	}

	type GroupKey struct {
		AccountID string
		TCode     string
		TDate     string
		TType     uint8
	}

	tds := []TransactionRecord{
		{ID: 1, AccountID: "A001", TCode: "161700", TDate: "2020-08-01", TType: 17, Amount: 23.0},
		{ID: 2, AccountID: "A001", TCode: "161700", TDate: "2020-08-01", TType: 17, Amount: 99.0},
		{ID: 3, AccountID: "A001", TCode: "161700", TDate: "2020-08-01", TType: 17, Amount: 25.0},

		{ID: 1, AccountID: "A001", TCode: "161700", TDate: "2020-08-01", TType: 24, Amount: 13.0},
		{ID: 2, AccountID: "A001", TCode: "161700", TDate: "2020-08-01", TType: 24, Amount: 69.0},
		{ID: 3, AccountID: "A001", TCode: "161700", TDate: "2020-08-01", TType: 24, Amount: 85.0},

		{ID: 4, AccountID: "A001", TCode: "161700", TDate: "2020-08-02", TType: 17, Amount: 11.0},
		{ID: 5, AccountID: "A001", TCode: "161700", TDate: "2020-08-02", TType: 17, Amount: 33.0},
		{ID: 6, AccountID: "A001", TCode: "161700", TDate: "2020-08-02", TType: 17, Amount: 57.0},
	}

	var results []GroupedRecord
	linq.From(tds).
		WhereT(func(r TransactionRecord) bool {
			return r.TType == 17 || r.TType == 24
		}).
		GroupByT(
			func(r TransactionRecord) GroupKey {
				return GroupKey{r.AccountID, r.TCode, r.TDate, r.TType}
			},
			func(r TransactionRecord) TransactionRecord { return r },
		).
		SelectT(func(g linq.Group) GroupedRecord {
			return GroupedRecord{
				AccountID: g.Key.(GroupKey).AccountID,
				TCode:     g.Key.(GroupKey).TCode,
				TDate:     g.Key.(GroupKey).TDate,
				TType:     g.Key.(GroupKey).TType,
				SumAmount: linq.From(g.Group).SelectT(func(r TransactionRecord) float64 { return r.Amount }).SumFloats(),
			}
		}).
		OrderByT(func(g GroupedRecord) string { return g.AccountID }).
		ThenByT(func(g GroupedRecord) string { return g.TCode }).
		ThenByT(func(g GroupedRecord) string { return g.TDate }).
		ThenByT(func(g GroupedRecord) uint8 { return g.TType }).
		ToSlice(&results)

[107295472]

I also want to use it like this, sum is in group by

[107295472]

Thanks, really strong

[wpecker]

thanks @cleitonmarx

[gatspy]

fantastic, thanks @cleitonmarx