Golang db.Open函数代码示例

// Trying to open an empty datasource, must fail.
func TestOpenFailed(t *testing.T) {
	_, err := db.Open(wrapperName, db.DataSource{})

	if err == nil {
		t.Errorf("Could not open database.")
	}
}

// Contributed by wei2912
// See: https://github.com/gosexy/db/issues/20#issuecomment-20167939
// Applying the BEGIN and END transaction optimizations.
func BenchmarkAppendDbItem_Transaction(b *testing.B) {
	sess, err := db.Open(wrapperName, settings)

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

	defer sess.Close()

	people := sess.ExistentCollection("people")
	people.Truncate()

	err = sess.Begin()
	if err != nil {
		b.Fatalf(err.Error())
	}

	for i := 0; i < b.N; i++ {
		_, err = people.Append(db.Item{"name": "john"})
		if err != nil {
			b.Fatalf(err.Error())
		}
	}

	err = sess.End()
	if err != nil {
		b.Fatalf(err.Error())
	}
}

// Tries to update rows.
func TestUpdate(t *testing.T) {
	var found int

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

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

	defer sess.Close()

	people := sess.ExistentCollection("people")

	// Update with map.
	people.Update(db.Cond{"name": "José"}, db.Set{"name": "Joseph"})

	found, _ = people.Count(db.Cond{"name": "Joseph"})

	if found != 1 {
		t.Fatalf("Could not update a recently appended item.")
	}

	// Update with struct.
	people.Update(db.Cond{"name": "Joseph"}, struct{ Name string }{"José"})

	found, _ = people.Count(db.Cond{"name": "José"})

	if found != 1 {
		t.Fatalf("Could not update a recently appended item.")
	}
}

// Truncates all collections/tables, one by one.
func TestTruncate(t *testing.T) {

	var err error

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

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

	defer sess.Close()

	collections := sess.Collections()

	for _, name := range collections {
		col := sess.ExistentCollection(name)
		col.Truncate()

		total, err := col.Count()

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

		if total != 0 {
			t.Errorf("Could not truncate.")
		}
	}

}

// Tries to add test data and relations.
func TestPopulate(t *testing.T) {

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

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

	defer sess.Close()

	people := sess.ExistentCollection("people")
	places := sess.ExistentCollection("places")
	children := sess.ExistentCollection("children")
	visits := sess.ExistentCollection("visits")

	values := []string{"Alaska", "Nebraska", "Alaska", "Acapulco", "Rome", "Singapore", "Alabama", "Cancún"}

	for i, value := range values {
		places.Append(db.Item{
			"code_id": i,
			"name":    value,
		})
	}

	results, _ := people.FindAll(
		db.Fields{"id", "name"},
		db.Sort{"name": "ASC", "id": -1},
	)

	for _, person := range results {

		// Has 5 children.

		for j := 0; j < 5; j++ {
			children.Append(db.Item{
				"name":      fmt.Sprintf("%s's child %d", person["name"], j+1),
				"parent_id": person["id"],
			})
		}

		// Lives in
		people.Update(
			db.Cond{"id": person["id"]},
			db.Set{"place_code_id": int(rand.Float32() * float32(len(results)))},
		)

		// Has visited
		for j := 0; j < 3; j++ {
			place, _ := places.Find(db.Cond{
				"code_id": int(rand.Float32() * float32(len(results))),
			})
			visits.Append(db.Item{
				"place_id":  place["id"],
				"person_id": person["id"],
			})
		}
	}

}

func main() {

	sess, err := db.Open("postgresql", settings)

	if err != nil {
		panic(err)
	}

	defer sess.Close()

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

	if err != nil {
		fmt.Printf("Please create the `animals` table: %s", err.Error())
		return
	}

	animals.Truncate()

	animals.Append(db.Item{
		"animal": "Bird",
		"young":  "Chick",
		"female": "Hen",
		"male":   "Cock",
		"group":  "flock",
	})

	animals.Append(db.Item{
		"animal": "Bovidae",
		"young":  "Calf",
		"female": "Cow",
		"male":   "Bull",
		"group":  "Herd",
	})

	animals.Append(db.Item{
		"animal": "Canidae",
		"young":  "Puppy, Pup",
		"female": "Bitch",
		"male":   "Dog",
		"group":  "Pack",
	})

	items, err := animals.FindAll()

	if err != nil {
		panic(err.Error())
	}

	for _, item := range items {
		fmt.Printf("animal: %s, young: %s\n", item["animal"], item["young"])
	}

}

// Tests relations between collections.
func TestRelation(t *testing.T) {
	sess, err := db.Open(wrapperName, settings)

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

	defer sess.Close()

	people, _ := sess.Collection("people")

	results, _ := people.FindAll(
		db.Relate{
			"lives_in": db.On{
				sess.ExistentCollection("places"),
				db.Cond{"code_id": "{place_code_id}"},
			},
		},
		db.RelateAll{
			"has_children": db.On{
				sess.ExistentCollection("children"),
				db.Cond{"parent_id": "{id}"},
			},
			"has_visited": db.On{
				sess.ExistentCollection("visits"),
				db.Cond{"person_id": "{id}"},
				db.Relate{
					"place": db.On{
						sess.ExistentCollection("places"),
						db.Cond{"id": "{place_id}"},
					},
				},
			},
		},
	)

	fmt.Printf("relations (1) %# v\n", pretty.Formatter(results))

	var testv string

	testv = dig.String(&results, 0, "lives_in", "name")

	if testv == "" {
		t.Fatalf("Test failed, expected some value.")
	}

	testv = dig.String(&results, 1, "has_children", 2, "name")

	if testv == "" {
		t.Fatalf("Test failed, expected some value.")
	}
}

func BenchmarkAppendStruct(b *testing.B) {
	sess, err := db.Open(wrapperName, settings)

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

	defer sess.Close()

	people := sess.ExistentCollection("people")
	people.Truncate()

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, err = people.Append(struct{ Name string }{"john"})
		if err != nil {
			b.Fatalf(err.Error())
		}
	}
}

// Tests limit and offset.
func TestLimitOffset(t *testing.T) {
	var err error

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

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

	defer sess.Close()

	people, _ := sess.Collection("people")

	items, _ := people.FindAll(db.Limit(2), db.Offset(1))

	if len(items) != 2 {
		t.Fatalf("Test failed")
	}

}

// Tries to delete rows.
func TestDelete(t *testing.T) {
	sess, err := db.Open(wrapperName, settings)

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

	defer sess.Close()

	people := sess.ExistentCollection("people")

	people.Remove(db.Cond{"name": "Juan"})

	result, _ := people.Find(db.Cond{"name": "Juan"})

	if len(result) > 0 {
		t.Fatalf("Could not remove a recently appended item.")
	}

}

func BenchmarkAppendRaw(b *testing.B) {
	sess, err := db.Open(wrapperName, settings)

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

	defer sess.Close()

	people := sess.ExistentCollection("people")
	people.Truncate()

	driver := sess.Driver().(*sql.DB)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, err := driver.Exec(`INSERT INTO people (name) VALUES("john")`)
		if err != nil {
			b.Fatalf(err.Error())
		}
	}
}

// Tests datatype conversions.
func TestDataTypes(t *testing.T) {
	var res db.Result
	var items []db.Item

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

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

	defer sess.Close()

	dataTypes := sess.ExistentCollection("data_types")

	dataTypes.Truncate()

	ids, err := dataTypes.Append(testValues)

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

	found, err := dataTypes.Count(db.Cond{"id": db.Id(ids[0])})

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

	if found == 0 {
		t.Errorf("Expecting an item.")
	}

	// Getting and reinserting (a db.Item).
	item, _ := dataTypes.Find()

	_, err = dataTypes.Append(item)

	if err == nil {
		t.Fatalf("Expecting duplicated-key error.")
	}

	delete(item, "id")

	_, err = dataTypes.Append(item)

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

	// Testing date ranges
	items, err = dataTypes.FindAll(db.Cond{
		"_date": time.Now(),
	})

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

	if len(items) > 0 {
		t.Fatalf("Expecting no results.")
	}

	items, err = dataTypes.FindAll(db.Cond{
		"_date <=": time.Now(),
	})

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

	if len(items) != 2 {
		t.Fatalf("Expecting some results.")
	}

	// Testing struct
	sresults := []testValuesStruct{}

	res, err = dataTypes.Query()

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

	err = res.All(&sresults)

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

	// Testing struct equality
	for _, item := range sresults {
		if reflect.DeepEqual(item, testValues) == false {
			t.Errorf("Struct is different.")
		}
	}

	// Testing maps
	results, _ := dataTypes.FindAll()

//.........这里部分代码省略.........

// Tests relations between collections using structs.
func TestRelationStruct(t *testing.T) {
	var err error
	var res db.Result

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

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

	defer sess.Close()

	people := sess.ExistentCollection("people")

	results := []struct {
		Id          int
		Name        string
		PlaceCodeId int
		LivesIn     struct {
			Name string
		}
		HasChildren []struct {
			Name string
		}
		HasVisited []struct {
			PlaceId int
			Place   struct {
				Name string
			}
		}
	}{}

	res, err = people.Query(
		db.Relate{
			"LivesIn": db.On{
				sess.ExistentCollection("places"),
				db.Cond{"code_id": "{PlaceCodeId}"},
			},
		},
		db.RelateAll{
			"HasChildren": db.On{
				sess.ExistentCollection("children"),
				db.Cond{"parent_id": "{Id}"},
			},
			"HasVisited": db.On{
				sess.ExistentCollection("visits"),
				db.Cond{"person_id": "{Id}"},
				db.Relate{
					"Place": db.On{
						sess.ExistentCollection("places"),
						db.Cond{"id": "{PlaceId}"},
					},
				},
			},
		},
	)

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

	err = res.All(&results)

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

	fmt.Printf("relations (2) %# v\n", pretty.Formatter(results))
}

// Appends maps and structs.
func TestAppend(t *testing.T) {

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

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

	defer sess.Close()

	_, err = sess.Collection("doesnotexists")

	if err == nil {
		t.Fatalf("Collection should not exists.")
	}

	people := sess.ExistentCollection("people")

	// To be inserted
	names := []string{
		"Juan",
		"José",
		"Pedro",
		"María",
		"Roberto",
		"Manuel",
		"Miguel",
	}

	var total int

	// Append db.Item
	people.Truncate()

	for _, name := range names {
		people.Append(db.Item{"name": name})
	}

	total, _ = people.Count()

	if total != len(names) {
		t.Fatalf("Could not append all items.")
	}

	// Append map[string]string
	people.Truncate()

	for _, name := range names {
		people.Append(map[string]string{"name": name})
	}

	total, _ = people.Count()

	if total != len(names) {
		t.Fatalf("Could not append all items.")
	}

	// Append map[string]interface{}
	people.Truncate()

	for _, name := range names {
		people.Append(map[string]interface{}{"name": name})
	}

	total, _ = people.Count()

	if total != len(names) {
		t.Fatalf("Could not append all items.")
	}

	// Append struct
	people.Truncate()

	for _, name := range names {
		people.Append(struct {
			ignoreMe string
			LastName string `ignorenil:"true"`
			// Must ignore OtherName and use "name" as column.
			OtherName string `field:"name",ignorenil:"true"`
			// Should not get inserted.
			nothing string
		}{"nuff said", "", name, "nothing"})
	}

	total, _ = people.Count()

	if total != len(names) {
		t.Fatalf("Could not append all items.")
	}

}

// Tries to find and fetch rows.
func TestFind(t *testing.T) {

	var err error
	var res db.Result

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

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

	defer sess.Close()

	/*
		// Testing simultaneous connection.
		sess2, err := db.Open(wrapperName, db.DataSource {
			Database: "mysql",
			Socket: socket,
			User: "root",
		})

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

		defer sess2.Close()
	*/

	people, _ := sess.Collection("people")

	// Testing Find()
	item, _ := people.Find(db.Cond{"name": "José"})

	if item["name"] != "José" {
		t.Fatalf("Could not find a recently appended item.")
	}

	// Fetch into map slice.
	dst := []map[string]string{}

	res, err = people.Query(db.Cond{"name": "José"})

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

	err = res.All(&dst)

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

	if len(dst) != 1 {
		t.Fatalf("Could not find a recently appended item.")
	}

	if dst[0]["name"] != "José" {
		t.Fatalf("Could not find a recently appended item.")
	}

	// Fetch into struct slice.
	dst2 := []struct {
		foo        string
		PersonName string `field:"name"`
		none       string
	}{}

	res, err = people.Query(db.Cond{"name": "José"})

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

	err = res.All(&dst2)

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

	if len(dst2) != 1 {
		t.Fatalf("Could not find a recently appended item.")
	}

	if dst2[0].PersonName != "José" {
		t.Fatalf("Could not find a recently appended item.")
	}

	// Fetch into map.
	dst3 := map[string]interface{}{}

	res, err = people.Query(db.Cond{"name": "José"})

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

	err = res.One(&dst3)

	if err != nil {
//.........这里部分代码省略.........