Golang NullString.Valid方法代碼示例

func checkStringForNull(eventStr string, event *sql.NullString) {
	if len(eventStr) == 0 {
		event.Valid = false
	} else {
		event.String = eventStr
		event.Valid = true
	}
}

func main() {
	db, err := sql.Open("postgres", "user=postgres password=pass dbname=mecab sslmode=disable")
	checkErr(err)
	//データの検索
	//rows, err := db.Query("SELECT * FROM words LIMIT 3")
	rows, err := db.Query("SELECT * FROM words WHERE first_char IS NULL")
	checkErr(err)

	for rows.Next() {
		var surface string
		var original string
		var reading string
		var first_c sql.NullString
		var last_c sql.NullString
		err = rows.Scan(&surface, &original, &reading, &first_c, &last_c)
		checkErr(err)
		/*
			fmt.Println(surface)
			fmt.Println(original)
			fmt.Println(reading)
			fmt.Println(reading[0:3])
			fmt.Println(reading[len(reading)-3 : len(reading)])
			fmt.Println(first_c)
			fmt.Println(last_c)
		*/

		first_c.String = reading[0:3]
		last_c.String = reading[len(reading)-3 : len(reading)]

		//データの更新
		stmt, err := db.Prepare("update words set first_char=$1, last_char=$2 where original=$3")
		checkErr(err)

		first_c.Valid = true
		last_c.Valid = true
		_, err = stmt.Exec(first_c.String, last_c.String, original)
		checkErr(err)

		/*
			affect, err := res.RowsAffected()
			checkErr(err)
			fmt.Println(affect)
		*/
	}

	db.Close()
	fmt.Println("finish")

}

func (w *DatabaseWorld) SaveThing(thing *Thing) (ok bool) {
	tabletext, err := json.Marshal(thing.Table)
	if err != nil {
		log.Println("Error serializing table data for thing", thing.Id, ":", err.Error())
		return false
	}

	var parent sql.NullInt64
	if thing.Parent != 0 {
		parent.Int64 = int64(thing.Parent)
		parent.Valid = true
	}
	var owner sql.NullInt64
	if thing.Owner != 0 && thing.Type.HasOwner() {
		owner.Int64 = int64(thing.Owner)
		owner.Valid = true
	}
	var program sql.NullString
	if thing.Program != nil {
		program.String = thing.Program.Text
		program.Valid = true
	}

	// TODO: save the allow list
	_, err = w.db.Exec("UPDATE thing SET name = $1, parent = $2, owner = $3, adminlist = $4, denylist = $5, tabledata = $6, program = $7 WHERE id = $8",
		thing.Name, parent, owner, thing.AdminList, thing.DenyList,
		types.JsonText(tabletext), program, thing.Id)
	if err != nil {
		log.Println("Error saving a thing", thing.Id, ":", err.Error())
		return false
	}
	return true
}

func (b *BaseConditionQuery) FRES(value interface{}) interface{} {
	if (*b.SqlClause).IsAllowEmptyStringQuery() {
		return value
	}
	switch value.(type) {
	case sql.NullString:
		var nstr sql.NullString = value.(sql.NullString)
		if nstr.Valid && nstr.String == "" {
			nstr.Valid = false
		}
		return nstr
	case *sql.NullString:
		var nstr *sql.NullString = value.(*sql.NullString)
		if nstr.Valid && nstr.String == "" {
			nstr.Valid = false
		}
		return nstr
	case string:
		var str string = value.(string)
		if str == "" {
			var null sql.NullString
			null.Valid = false
			return null
		}
	case *string:
		var strx string = *value.(*string)
		if strx == "" {
			var null sql.NullString
			null.Valid = false
			return null
		}
	default:
		panic("This type not supported :" + GetType(value))
	}
	return value
}

func (b *BasePmb) CheckAndComvertEmptyToNull(value interface{}) interface{} {
	if DBCurrent_I.EmptyStringParameterAllowed {
		return value
	}
	switch value.(type) {
	case sql.NullString:
		var nstr sql.NullString = value.(sql.NullString)
		if nstr.Valid && nstr.String == "" {
			nstr.Valid = false
		}
		return nstr
	case *sql.NullString:
		var nstr *sql.NullString = value.(*sql.NullString)
		if nstr.Valid && nstr.String == "" {
			nstr.Valid = false
		}
		return nstr
	case string:
		var str string = value.(string)
		if str == "" {
			var null sql.NullString
			null.Valid = false
			return null
		}
	case *string:
		var strx string = *value.(*string)
		if strx == "" {
			var null sql.NullString
			null.Valid = false
			return null
		}
	default:
		panic("This type not supported :" + GetType(value))
	}
	return value
}

func (h Hstore) Value() (driver.Value, error) {
	hstore := hstore.Hstore{Map: map[string]sql.NullString{}}
	if len(h) == 0 {
		return nil, nil
	}

	for key, value := range h {
		var s sql.NullString
		if value != nil {
			s.String = *value
			s.Valid = true
		}
		hstore.Map[key] = s
	}
	return hstore.Value()
}

func (db *SQLDB) CreateContainer(container Container, ttl time.Duration) (SavedContainer, error) {
	if !(isValidCheckID(container.ContainerIdentifier) || isValidStepID(container.ContainerIdentifier)) {
		return SavedContainer{}, ErrInvalidIdentifier
	}

	tx, err := db.conn.Begin()
	if err != nil {
		return SavedContainer{}, err
	}

	defer tx.Rollback()

	checkSource, err := json.Marshal(container.CheckSource)
	if err != nil {
		return SavedContainer{}, err
	}

	envVariables, err := json.Marshal(container.EnvironmentVariables)
	if err != nil {
		return SavedContainer{}, err
	}

	user := container.User

	interval := fmt.Sprintf("%d second", int(ttl.Seconds()))

	if container.PipelineName != "" && container.PipelineID == 0 {
		// containers that belong to some pipeline must be identified by pipeline ID not name
		return SavedContainer{}, errors.New("container metadata must include pipeline ID")
	}
	var pipelineID sql.NullInt64
	if container.PipelineID != 0 {
		pipelineID.Int64 = int64(container.PipelineID)
		pipelineID.Valid = true
	}

	var resourceID sql.NullInt64
	if container.ResourceID != 0 {
		resourceID.Int64 = int64(container.ResourceID)
		resourceID.Valid = true
	}

	var resourceTypeVersion string
	if container.ResourceTypeVersion != nil {
		resourceTypeVersionBytes, err := json.Marshal(container.ResourceTypeVersion)
		if err != nil {
			return SavedContainer{}, err
		}
		resourceTypeVersion = string(resourceTypeVersionBytes)
	}

	var buildID sql.NullInt64
	if container.BuildID != 0 {
		buildID.Int64 = int64(container.BuildID)
		buildID.Valid = true
	}

	workerName := container.WorkerName
	if workerName == "" {
		workerName = container.WorkerName
	}

	var attempts sql.NullString
	if len(container.Attempts) > 0 {
		attemptsBlob, err := json.Marshal(container.Attempts)
		if err != nil {
			return SavedContainer{}, err
		}
		attempts.Valid = true
		attempts.String = string(attemptsBlob)
	}

	var imageResourceSource sql.NullString
	if container.ImageResourceSource != nil {
		marshaled, err := json.Marshal(container.ImageResourceSource)
		if err != nil {
			return SavedContainer{}, err
		}

		imageResourceSource.String = string(marshaled)
		imageResourceSource.Valid = true
	}

	var imageResourceType sql.NullString
	if container.ImageResourceType != "" {
		imageResourceType.String = container.ImageResourceType
		imageResourceType.Valid = true
	}

	_, err = tx.Exec(`
		INSERT INTO containers (handle, resource_id, step_name, pipeline_id, build_id, type, worker_name, expires_at, ttl, check_type, check_source, plan_id, working_directory, env_variables, attempts, stage, image_resource_type, image_resource_source, process_user, resource_type_version)
		VALUES ($1, $2, $3, $4, $5, $6, $7, NOW() + $8::INTERVAL, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $20)`,
		container.Handle,
		resourceID,
		container.StepName,
		pipelineID,
		buildID,
		container.Type.String(),
		workerName,
		interval,
//.........這裏部分代碼省略.........

func (db *SQLDB) CreateContainer(container Container, ttl time.Duration) (Container, error) {
	if !isValidID(container.ContainerIdentifier) {
		return Container{}, ErrInvalidIdentifier
	}

	tx, err := db.conn.Begin()
	if err != nil {
		return Container{}, err
	}

	checkSource, err := json.Marshal(container.CheckSource)
	if err != nil {
		return Container{}, err
	}

	envVariables, err := json.Marshal(container.EnvironmentVariables)
	if err != nil {
		return Container{}, err
	}

	user := container.User

	interval := fmt.Sprintf("%d second", int(ttl.Seconds()))

	var pipelineID sql.NullInt64
	if container.PipelineName != "" {
		pipeline, err := db.GetPipelineByTeamNameAndName(atc.DefaultTeamName, container.PipelineName)
		if err != nil {
			return Container{}, fmt.Errorf("failed to find pipeline: %s", err.Error())
		}
		pipelineID.Int64 = int64(pipeline.ID)
		pipelineID.Valid = true
	}

	var resourceID sql.NullInt64
	if container.ResourceID != 0 {
		resourceID.Int64 = int64(container.ResourceID)
		resourceID.Valid = true
	}

	var buildID sql.NullInt64
	if container.BuildID != 0 {
		buildID.Int64 = int64(container.BuildID)
		buildID.Valid = true
	}

	workerName := container.WorkerName
	if workerName == "" {
		workerName = container.WorkerName
	}

	var attempts sql.NullString
	if len(container.Attempts) > 0 {
		attemptsBlob, err := json.Marshal(container.Attempts)
		if err != nil {
			return Container{}, err
		}
		attempts.Valid = true
		attempts.String = string(attemptsBlob)
	}

	var imageResourceSource sql.NullString
	if container.ImageResourceSource != nil {
		marshaled, err := json.Marshal(container.ImageResourceSource)
		if err != nil {
			return Container{}, err
		}

		imageResourceSource.String = string(marshaled)
		imageResourceSource.Valid = true
	}

	var imageResourceType sql.NullString
	if container.ImageResourceType != "" {
		imageResourceType.String = container.ImageResourceType
		imageResourceType.Valid = true
	}

	defer tx.Rollback()

	_, err = tx.Exec(`
		INSERT INTO containers (handle, resource_id, step_name, pipeline_id, build_id, type, worker_name, expires_at, check_type, check_source, plan_id, working_directory, env_variables, attempts, stage, image_resource_type, image_resource_source, process_user)
		VALUES ($1, $2, $3, $4, $5, $6,  $7, NOW() + $8::INTERVAL, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18)`,
		container.Handle,
		resourceID,
		container.StepName,
		pipelineID,
		buildID,
		container.Type.String(),
		workerName,
		interval,
		container.CheckType,
		checkSource,
		string(container.PlanID),
		container.WorkingDirectory,
		envVariables,
		attempts,
		string(container.Stage),
		imageResourceType,
		imageResourceSource,
//.........這裏部分代碼省略.........

func (db *SQLDB) FindContainerByIdentifier(id ContainerIdentifier) (Container, bool, error) {
	err := deleteExpired(db)
	if err != nil {
		return Container{}, false, err
	}

	var imageResourceSource sql.NullString
	if id.ImageResourceSource != nil {
		marshaled, err := json.Marshal(id.ImageResourceSource)
		if err != nil {
			return Container{}, false, err
		}

		imageResourceSource.String = string(marshaled)
		imageResourceSource.Valid = true
	}

	var imageResourceType sql.NullString
	if id.ImageResourceType != "" {
		imageResourceType.String = id.ImageResourceType
		imageResourceType.Valid = true
	}

	var containers []Container

	selectQuery := `
		SELECT ` + containerColumns + `
		FROM containers c ` + containerJoins + `
		`

	conditions := []string{}
	params := []interface{}{}

	if isValidCheckID(id) {
		checkSourceBlob, err := json.Marshal(id.CheckSource)
		if err != nil {
			return Container{}, false, err
		}

		conditions = append(conditions, "resource_id = $1")
		params = append(params, id.ResourceID)

		conditions = append(conditions, "check_type = $2")
		params = append(params, id.CheckType)

		conditions = append(conditions, "check_source = $3")
		params = append(params, checkSourceBlob)

		conditions = append(conditions, "stage = $4")
		params = append(params, string(id.Stage))
	} else if isValidStepID(id) {
		conditions = append(conditions, "build_id = $1")
		params = append(params, id.BuildID)

		conditions = append(conditions, "plan_id = $2")
		params = append(params, string(id.PlanID))

		conditions = append(conditions, "stage = $3")
		params = append(params, string(id.Stage))
	} else {
		return Container{}, false, ErrInvalidIdentifier
	}

	if imageResourceSource.Valid && imageResourceType.Valid {
		conditions = append(conditions, fmt.Sprintf("image_resource_source = $%d", len(params)+1))
		params = append(params, imageResourceSource.String)

		conditions = append(conditions, fmt.Sprintf("image_resource_type = $%d", len(params)+1))
		params = append(params, imageResourceType.String)
	} else {
		conditions = append(conditions, "image_resource_source IS NULL")
		conditions = append(conditions, "image_resource_type IS NULL")
	}

	selectQuery += "WHERE " + strings.Join(conditions, " AND ")

	rows, err := db.conn.Query(selectQuery, params...)
	if err != nil {
		return Container{}, false, err
	}

	for rows.Next() {
		container, err := scanContainer(rows)
		if err != nil {
			return Container{}, false, nil
		}
		containers = append(containers, container)
	}

	switch len(containers) {
	case 0:
		return Container{}, false, nil

	case 1:
		return containers[0], true, nil

	default:
		return Container{}, false, ErrMultipleContainersFound
	}
}

func CreateNullString(s string) sql.NullString {
	var ns sql.NullString
	ns.Valid = true
	ns.String = s
	return ns
}

func setString(s *sql.NullString, v string) {
	if v != "" {
		s.Valid = true
		s.String = v
	}
}