db

Documentation

Overview

Package db represents database services abstraction layer. It provides a set of interfaces and helpers to interact with database storage services.

So, when package decides to store something in database it should work with this package instead of trying to interact with concrete database engine (as Ottemo supposing ability to work with different databases).

Providing Ottemo with a new database engine supposes implementation of "InterfaceDBEngine" with following registration for db package.

For database type specification you should refer this package for possible types.

Example:
--------
collection, err := db.GetCollection( myCollectionName )
if err != nil {
	return env.ErrorDispatch(err)
}

collection.AddColumn("customer_id", db.ConstTypeID, false)
collection.AddColumn("customer_email", db.TypeWPrecision(db.ConstTypeVarchar, 100), true)
collection.AddColumn("bonus_code", db.ConstTypeInteger, false)
collection.AddColumn("bonus_amount", db.ConstTypeInteger, false)

Index

• Constants
• func ConvertTypeFromDbToGo(value interface{}, valueType string) interface{}
• func OnDatabaseStart() error
• func RegisterDBEngine(newEngine InterfaceDBEngine) error
• func RegisterOnDatabaseStart(callback func() error)
• func TypeArrayOf(dataType string) string
• func TypeIsArray(dataType string) bool
• func TypeIsFloat(dataType string) bool
• func TypeIsString(dataType string) bool
• func TypeParse(typeName string) utils.DataType
• func TypeWPrecision(dataType string, precision int) string
• func TypeWPrecisionAndScale(dataType string, precision int, scale int) string
• type DBConnector
  • func NewDBConnector(connector InterfaceDBConnector) *DBConnector
  • func (it *DBConnector) Connect() error
  • func (it *DBConnector) ConnectAsync() error
• type InterfaceDBCollection
  • func GetCollection(CollectionName string) (InterfaceDBCollection, error)
• type InterfaceDBConnector
• type InterfaceDBEngine
  • func GetDBEngine() InterfaceDBEngine

Constants

const (
	ConstTypeID       = utils.ConstDataTypeID
	ConstTypeBoolean  = utils.ConstDataTypeBoolean
	ConstTypeVarchar  = utils.ConstDataTypeVarchar
	ConstTypeText     = utils.ConstDataTypeText
	ConstTypeInteger  = utils.ConstDataTypeInteger
	ConstTypeDecimal  = utils.ConstDataTypeDecimal
	ConstTypeMoney    = utils.ConstDataTypeMoney
	ConstTypeFloat    = utils.ConstDataTypeFloat
	ConstTypeDatetime = utils.ConstDataTypeDatetime
	ConstTypeJSON     = utils.ConstDataTypeJSON

	ConstErrorModule = "db"
	ConstErrorLevel  = env.ConstErrorLevelService
)

Package global constants

Functions

func ConvertTypeFromDbToGo

func ConvertTypeFromDbToGo(value interface{}, valueType string) interface{}

ConvertTypeFromDbToGo returns object that represents GO side value for given valueType

func OnDatabaseStart

func OnDatabaseStart() error

OnDatabaseStart fires database service start event (callback handling)

func RegisterDBEngine

func RegisterDBEngine(newEngine InterfaceDBEngine) error

RegisterDBEngine registers database service in the system

• will cause error if there are couple candidates for that role

func RegisterOnDatabaseStart

func RegisterOnDatabaseStart(callback func() error)

RegisterOnDatabaseStart registers new callback on database service start

func TypeArrayOf

func TypeArrayOf(dataType string) string

TypeArrayOf shortcut for utils.DataTypeArrayOf

func TypeIsArray

func TypeIsArray(dataType string) bool

TypeIsArray shortcut for utils.DataTypeIsArray

func TypeIsFloat

func TypeIsFloat(dataType string) bool

TypeIsFloat shortcut for utils.DataTypeIsFloat

func TypeIsString

func TypeIsString(dataType string) bool

TypeIsString shortcut for utils.DataTypeIsString

func TypeParse

func TypeParse(typeName string) utils.DataType

TypeParse shortcut for utils.DataTypeParse

func TypeWPrecision

func TypeWPrecision(dataType string, precision int) string

TypeWPrecision shortcut for utils.DataTypeWPrecision

func TypeWPrecisionAndScale

func TypeWPrecisionAndScale(dataType string, precision int, scale int) string

TypeWPrecisionAndScale shortcut for utils.DataTypeWPrecisionAndScale

Types

type DBConnector

type DBConnector struct {
	// contains filtered or unexported fields
}

DBConnector takes logic of connection to DB and keeps it alive

func NewDBConnector

func NewDBConnector(connector InterfaceDBConnector) *DBConnector

NewDBConnector returns new DBConnector instance

func (*DBConnector) Connect

func (it *DBConnector) Connect() error

Connect implements connection process algorithm

func (*DBConnector) ConnectAsync

func (it *DBConnector) ConnectAsync() error

ConnectAsync makes connection process asynchronously

type InterfaceDBCollection

type InterfaceDBCollection interface {
	Load() ([]map[string]interface{}, error)
	LoadByID(id string) (map[string]interface{}, error)

	Save(map[string]interface{}) (string, error)

	Delete() (int, error)
	DeleteByID(id string) error

	Iterate(iteratorFunc func(record map[string]interface{}) bool) error

	Count() (int, error)
	Distinct(columnName string) ([]interface{}, error)

	SetupFilterGroup(groupName string, orSequence bool, parentGroup string) error
	RemoveFilterGroup(groupName string) error
	AddGroupFilter(groupName string, columnName string, operator string, value interface{}) error

	AddStaticFilter(columnName string, operator string, value interface{}) error
	AddFilter(columnName string, operator string, value interface{}) error

	ClearFilters() error

	AddSort(columnName string, Desc bool) error
	ClearSort() error

	SetResultColumns(columns ...string) error

	SetLimit(offset int, limit int) error

	ListColumns() map[string]string
	GetColumnType(columnName string) string
	HasColumn(columnName string) bool

	AddColumn(columnName string, columnType string, indexed bool) error
	RemoveColumn(columnName string) error
}

InterfaceDBCollection interface to access particular table/collection of database

func GetCollection

func GetCollection(CollectionName string) (InterfaceDBCollection, error)

GetCollection returns database collection or error otherwise

type InterfaceDBConnector

type InterfaceDBConnector interface {
	GetConnectionParams() interface{}
	Connect(connectionParams interface{}) error
	AfterConnect(connectionParams interface{}) error

	Ping() error
	GetValidationInterval() time.Duration
	Reconnect(connectionParams interface{}) error

	IsConnected() bool
	SetConnected(connected bool)

	GetEngineName() string
	LogConnection(message string)
}

InterfaceDBConnector interface to connect to database and keep connection alive

type InterfaceDBEngine

type InterfaceDBEngine interface {
	GetName() string
	IsConnected() bool

	CreateCollection(Name string) error
	GetCollection(Name string) (InterfaceDBCollection, error)
	HasCollection(Name string) bool

	RawQuery(query string) (map[string]interface{}, error)
}

InterfaceDBEngine represents interface to access database engine

func GetDBEngine

func GetDBEngine() InterfaceDBEngine

GetDBEngine returns currently used database service implementation