Fixes #322

src/github.com/stellar/horizon/db2/core/order_book_summary.go

@@ -159,7 +159,7 @@ FROM
 		co.priced,
 		co.price
 
-	ORDER BY co.price DESC
+	ORDER BY co.price ASC
 	
 	LIMIT $1
 )) summary

src/github.com/stellar/horizon/db2/core/order_book_summary_test.go

@@ -85,17 +85,17 @@ func TestGetOrderBookSummary_Regress310(t *testing.T) {
 	// 0.1, 0.2, and 0.3 should appear first, when the
 	// query is correct.  In a failing scenario the 0.2
 	// transaction should not appear.
-
-	tt.Assert.Equal(0.1, summary[0].Pricef)
-	tt.Assert.Equal(0.2, summary[1].Pricef)
-	tt.Assert.Equal(0.3, summary[2].Pricef)
+	bids := summary.Bids()
+	tt.Assert.Equal(10.2, bids[0].Pricef)
+	tt.Assert.Equal(10.1, bids[1].Pricef)
+	tt.Assert.Equal(10.0, bids[2].Pricef)
 
 	// validate the inverse order book is correct as well
 	err = q.GetOrderBookSummary(&summary, buying, selling)
 	tt.Require.NoError(err)
 	tt.Require.Len(summary, 20)
-
-	tt.Assert.Equal(1.0/10.2, summary[0].Pricef)
-	tt.Assert.Equal(1.0/10.1, summary[1].Pricef)
-	tt.Assert.Equal(1.0/10.0, summary[2].Pricef)
+	asks := summary.Asks()
+	tt.Assert.Equal(1.0/10.2, asks[0].Pricef)
+	tt.Assert.Equal(1.0/10.1, asks[1].Pricef)
+	tt.Assert.Equal(1.0/10.0, asks[2].Pricef)
 }