Golang Result.Next方法代码示例

// Attempts to fetch results one by one.
func TestResultFetch(t *testing.T) {
	var err error
	var res db.Result
	var sess db.Database
	var artist db.Collection

	if sess, err = db.Open(Adapter, settings); err != nil {
		t.Fatal(err)
	}

	defer sess.Close()

	if artist, err = sess.Collection("artist"); err != nil {
		t.Fatal(err)
	}

	// Dumping into a map.
	rowMap := map[string]interface{}{}

	res = artist.Find()

	for {
		err = res.Next(&rowMap)

		if err == db.ErrNoMoreRows {
			break
		}

		if err == nil {
			if to.Int64(rowMap["id"]) == 0 {
				t.Fatalf("Expecting a not null ID.")
			}
			if to.String(rowMap["name"]) == "" {
				t.Fatalf("Expecting a name.")
			}
		} else {
			t.Fatal(err)
		}
	}

	res.Close()

	// Dumping into an struct with no tags.
	rowStruct := struct {
		ID   uint64
		Name string
	}{}

	res = artist.Find()

	for {
		err = res.Next(&rowStruct)

		if err == db.ErrNoMoreRows {
			break
		}

		if err == nil {
			if rowStruct.ID == 0 {
				t.Fatalf("Expecting a not null ID.")
			}
			if rowStruct.Name == "" {
				t.Fatalf("Expecting a name.")
			}
		} else {
			t.Fatal(err)
		}
	}

	res.Close()

	// Dumping into a tagged struct.
	rowStruct2 := struct {
		Value1 uint64 `field:"id"`
		Value2 string `field:"name"`
	}{}

	res = artist.Find()

	for {
		err = res.Next(&rowStruct2)

		if err == db.ErrNoMoreRows {
			break
		}

		if err == nil {
			if rowStruct2.Value1 == 0 {
				t.Fatalf("Expecting a not null ID.")
			}
			if rowStruct2.Value2 == "" {
				t.Fatalf("Expecting a name.")
			}
		} else {
			t.Fatal(err)
		}
	}

	res.Close()
//.........这里部分代码省略.........

func TestFibonacci(t *testing.T) {
	var err error
	var res db.Result
	var total uint64

	for _, wrapper := range wrappers {
		if settings[wrapper] == nil {
			t.Fatalf(`No such settings entry for wrapper %s.`, wrapper)
		} else {
			var sess db.Database

			sess, err = db.Open(wrapper, *settings[wrapper])
			if err != nil {
				t.Fatalf(`Test for wrapper %s failed: %q`, wrapper, err)
			}
			defer sess.Close()

			var col db.Collection
			col, err = sess.Collection("fibonacci")

			if err != nil {
				if wrapper == `mongo` && err == db.ErrCollectionDoesNotExist {
					// Expected error with mongodb.
				} else {
					t.Fatalf(`Could not use collection with wrapper %s: %q`, wrapper, err)
				}
			}

			// Adding some items.
			var i uint64
			for i = 0; i < 10; i++ {
				item := fibonacci{Input: i, Output: fib(i)}
				_, err = col.Append(item)
				if err != nil {
					t.Fatalf(`Could not append item with wrapper %s: %q`, wrapper, err)
				}
			}

			// Testing sorting by function.
			res = col.Find(
				// 5, 6, 7, 3
				db.Or{
					db.And{
						db.Cond{"input >=": 5},
						db.Cond{"input <=": 7},
					},
					db.Cond{"input": 3},
				},
			)

			// Testing sort by function.
			switch wrapper {
			case `postgresql`:
				res = res.Sort(db.Raw{`RANDOM()`})
			case `sqlite`:
				res = res.Sort(db.Raw{`RANDOM()`})
			case `mysql`:
				res = res.Sort(db.Raw{`RAND()`})
			}

			total, err = res.Count()

			if err != nil {
				t.Fatalf(`%s: %q`, wrapper, err)
			}

			if total != 4 {
				t.Fatalf("%s: Expecting a count of 4, got %d.", wrapper, total)
			}

			// Find() with IN/$in
			var whereIn db.Cond

			switch wrapper {
			case `mongo`:
				whereIn = db.Cond{"input": db.Func{"$in", []int{3, 5, 6, 7}}}
			default:
				whereIn = db.Cond{"input": db.Func{"IN", []int{3, 5, 6, 7}}}
			}

			res = col.Find(whereIn).Sort("input")

			total, err = res.Count()

			if err != nil {
				t.Fatalf(`%s: %q`, wrapper, err)
			}

			if total != 4 {
				t.Fatalf(`Expecting a count of 4.`)
			}

			res = res.Skip(1).Limit(2)

			for {
				var item fibonacci
				err = res.Next(&item)
				if err == nil {
					switch item.Input {
					case 5:
//.........这里部分代码省略.........

// This test uses and result and tries to fetch items one by one.
func TestResultFetch(t *testing.T) {

	var err error
	var res db.Result

	// Opening database.
	sess, err := db.Open(wrapperName, settings)

	if err != nil {
		t.Fatalf(err.Error())
	}

	// We should close the database when it's no longer in use.
	defer sess.Close()

	artist, err := sess.Collection("artist")

	if err != nil {
		t.Fatalf(err.Error())
	}

	// Testing map
	res = artist.Find()

	row_m := map[string]interface{}{}

	for {
		err = res.Next(&row_m)

		if err == db.ErrNoMoreRows {
			// No more row_ms left.
			break
		}

		if err == nil {
			if to.Int64(row_m["id"]) == 0 {
				t.Fatalf("Expecting a not null ID.")
			}
			if to.String(row_m["name"]) == "" {
				t.Fatalf("Expecting a name.")
			}
		} else {
			t.Fatalf(err.Error())
		}
	}

	res.Close()

	// Testing struct
	row_s := struct {
		Id   uint64
		Name string
	}{}

	res = artist.Find()

	for {
		err = res.Next(&row_s)

		if err == db.ErrNoMoreRows {
			// No more row_s' left.
			break
		}

		if err == nil {
			if row_s.Id == 0 {
				t.Fatalf("Expecting a not null ID.")
			}
			if row_s.Name == "" {
				t.Fatalf("Expecting a name.")
			}
		} else {
			t.Fatalf(err.Error())
		}
	}

	res.Close()

	// Testing tagged struct
	row_t := struct {
		Value1 uint64 `field:"id"`
		Value2 string `field:"name"`
	}{}

	res = artist.Find()

	for {
		err = res.Next(&row_t)

		if err == db.ErrNoMoreRows {
			// No more row_t's left.
			break
		}

		if err == nil {
			if row_t.Value1 == 0 {
				t.Fatalf("Expecting a not null ID.")
			}
			if row_t.Value2 == "" {
//.........这里部分代码省略.........