gorm

package
v0.16.5 Latest Latest
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 Go to latest Published: Jul 10, 2019 License: Apache-2.0 Imports: 23 Imported by: 3

README

GORM

This package contains a set of utilities for famous GORM library. If used together they can significantly help you to enable persistency in your application.

Collection Operators

The package provides some helpers which are able to apply collection operators defined in query package to a GORM query.

Applying query.Filtering
...
// given that Person is a protobuf message and PersonORM is a corresponding GORM model
db, assoc, err = gorm.ApplyFiltering(ctx, db, filtering, &PersonORM{}, &Person{})
if err != nil {
    ...
}
// Join required associations(for nested field support)
db, err = gorm.JoinAssociations(ctx, db, assoc, &PersonORM{})
if err != nil {
    ...
}
var people []Person
db.Find(&people)
...
Applying query.Sorting
...
db, assoc, err = gorm.ApplySorting(ctx, db, sorting, &PersonORM{}, &Person{})
if err != nil {
    ...
}
// Join required associations(for nested field support)
db, err = gorm.JoinAssociations(ctx, db, assoc, &PersonORM{})
if err != nil {
    ...
}
var people []Person
db.Find(&people)
...
Applying query.Pagination
...
db = gorm.ApplyPagination(ctx, db, pagination, &PersonORM{}, &Person{})
if err != nil {
    ...
}
var people []Person
db.Find(&people)
...
Applying query.FieldSelection
...
db, err = gorm.ApplyFieldSelection(ctx, db, fields, &PersonORM{}, &Person{})
if err != nil {
    ...
}
var people []Person
db.Find(&people)
...
Applying everything
...
db, err = gorm.ApplyCollectionOperators(ctx, db, &PersonORM{}, &Person{}, filtering, sorting, pagination, fields)
if err != nil {
    ...
}
var people []Person
db.Find(&people)
...

Transaction Management

We provide transaction management by offering gorm.Transaction wrapper and gorm.UnaryServerInterceptor. The gorm.Transaction works as a singleton to prevent an application of creating more than one transaction instance per incoming request. The gorm.UnaryServerInterceptor performs management on transactions. Interceptor creates new transaction on each incoming request and commits it if request finishes without error, otherwise transaction is aborted. The created transaction is stored in context.Context and passed to the request handler as usual.

NOTE Client is responsible to call txn.Begin() to open transaction.

// add gorm interceptor to the chain
  server := grpc.NewServer(
    grpc.UnaryInterceptor(
      grpc_middleware.ChainUnaryServer( // middleware chain
        ...
        gorm.UnaryServerInterceptor(), // transaction management
        ...
      ),
    ),
  )

import (
	"github.com/rigoiot/atlas-app-toolkit/gorm"
)

func (s *MyService) MyMethod(ctx context.Context, req *MyMethodRequest) (*MyMethodResponse, error) {
	// extract gorm transaction from context
	txn, ok := gorm.FromContext(ctx)
	if !ok {
		return panic("transaction is not opened") // don't panic in production!
	}
	// start transaction
	gormDB := txn.Begin()
	if err := gormDB.Error; err != nil {
		return nil, err
	}
	// do stuff with *gorm.DB
	return &MyMethodResponse{...}, nil
}

Migration version validation

The toolkit does not require any specific method for database provisioning and setup. However, if golang-migrate or the infobloxopen fork of it is used, a couple helper functions are provided here for verifying that the database version matches a required version without having to import the entire migration package.

Documentation

Index

Constants

This section is empty.

Variables

View Source 
var (
	ErrCtxTxnMissing = errors.New("Database transaction for request missing in context")
	ErrCtxTxnNoDB    = errors.New("Transaction in context, but DB is nil")
)

Functions

func ApplyCollectionOperators 

func ApplyCollectionOperators(ctx context.Context, db *gorm.DB, obj interface{}, pb proto.Message, f *query.Filtering, s *query.Sorting, p *query.Pagination, fs *query.FieldSelection) (*gorm.DB, error)

ApplyCollectionOperators applies collection operators to gorm instance db.

func ApplyFieldSelection 

func ApplyFieldSelection(ctx context.Context, db *gorm.DB, fs *query.FieldSelection, obj interface{}) (*gorm.DB, error)

ApplyFieldSelection applies field selection operator fs to gorm instance db.

func ApplyFiltering 

func ApplyFiltering(ctx context.Context, db *gorm.DB, f *query.Filtering, obj interface{}, pb proto.Message) (*gorm.DB, map[string]struct{}, error)

ApplyFiltering applies filtering operator f to gorm instance db.

func ApplyPagination 

func ApplyPagination(ctx context.Context, db *gorm.DB, p *query.Pagination) *gorm.DB

ApplyPagination applies pagination operator p to gorm instance db.

func ApplySorting 

func ApplySorting(ctx context.Context, db *gorm.DB, s *query.Sorting, obj interface{}) (*gorm.DB, map[string]struct{}, error)

ApplySorting applies sorting operator s to gorm instance db.

func BeginFromContext added in v0.6.0 

func BeginFromContext(ctx context.Context) (*gorm.DB, error)

func FieldSelectionStringToGorm added in v0.7.0 

func FieldSelectionStringToGorm(ctx context.Context, fs string, obj interface{}) ([]string, error)

FieldSelectionStringToGorm is a shortcut to parse a string into FieldSelection struct and receive a list of associations to preload.

func FieldSelectionToGorm added in v0.7.0 

func FieldSelectionToGorm(ctx context.Context, fs *query.FieldSelection, obj interface{}) ([]string, error)

FieldSelectionToGorm receives FieldSelection struct and returns a list of associations to preload.

func FilterStringToGorm 

func FilterStringToGorm(ctx context.Context, filter string, obj interface{}, pb proto.Message) (string, []interface{}, map[string]struct{}, error)

FilterStringToGorm is a shortcut to parse a filter string using default FilteringParser implementation and call FilteringToGorm on the returned filtering expression.

func FilteringToGorm 

func FilteringToGorm(ctx context.Context, m *query.Filtering, obj interface{}, pb proto.Message) (string, []interface{}, map[string]struct{}, error)

FilteringToGorm returns GORM Plain SQL representation of the filtering expression.

func HandleFieldPath added in v0.7.0 

func HandleFieldPath(ctx context.Context, fieldPath []string, obj interface{}) (string, string, error)

HandleFieldPath converts fieldPath to appropriate db string for use in where/order by clauses according to obj GORM model. If fieldPath cannot be found in obj then original fieldPath is returned to allow tables joined by a third party. If association join is required to resolve the field path then it's name is returned as a second return value.

func JoinAssociations added in v0.7.0 

func JoinAssociations(ctx context.Context, db *gorm.DB, assoc map[string]struct{}, obj interface{}) (*gorm.DB, error)

JoinAssociations joins obj's associations from assoc to the current gorm query.

func JoinInfo added in v0.7.0 

func JoinInfo(ctx context.Context, obj interface{}, assoc string) (string, []string, []string, error)

JoinInfo extracts the following information for assoc association of obj: - association table name - source join keys - target join keys

func LogicalOperatorToGorm 

func LogicalOperatorToGorm(ctx context.Context, lop *query.LogicalOperator, obj interface{}, pb proto.Message) (string, []interface{}, map[string]struct{}, error)

LogicalOperatorToGorm returns GORM Plain SQL representation of the logical operator.

func MergeWithMask added in v0.8.0 

func MergeWithMask(source, dest interface{}, mask *ptypes.FieldMask) error

MergeWithMask will take the fields of `source` that are included as paths in `mask` and write them to the corresponding fields of `dest`

func NewContext added in v0.5.0 

func NewContext(parent context.Context, txn *Transaction) context.Context

NewContext returns a new Context that carries value txn.

func NullConditionToGorm 

func NullConditionToGorm(ctx context.Context, c *query.NullCondition, obj interface{}, pb proto.Message) (string, []interface{}, map[string]struct{}, error)

NullConditionToGorm returns GORM Plain SQL representation of the null condition.

func NumberArrayConditionToGorm added in v0.15.0 

func NumberArrayConditionToGorm(ctx context.Context, c *query.NumberArrayCondition, obj interface{}, pb proto.Message) (string, []interface{}, map[string]struct{}, error)

func NumberConditionToGorm 

func NumberConditionToGorm(ctx context.Context, c *query.NumberCondition, obj interface{}, pb proto.Message) (string, []interface{}, map[string]struct{}, error)

NumberConditionToGorm returns GORM Plain SQL representation of the number condition.

func StringArrayConditionToGorm added in v0.15.0 

func StringArrayConditionToGorm(ctx context.Context, c *query.StringArrayCondition, obj interface{}, pb proto.Message) (string, []interface{}, map[string]struct{}, error)

func StringConditionToGorm 

func StringConditionToGorm(ctx context.Context, c *query.StringCondition, obj interface{}, pb proto.Message) (string, []interface{}, map[string]struct{}, error)

StringConditionToGorm returns GORM Plain SQL representation of the string condition.

func UnaryServerInterceptor added in v0.5.0 

func UnaryServerInterceptor(db *gorm.DB) grpc.UnaryServerInterceptor

UnaryServerInterceptor returns grpc.UnaryServerInterceptor that manages a `*Transaction` instance. New *Transaction instance is created before grpc.UnaryHandler call. Client is responsible to call `txn.Begin()` to open transaction. If call of grpc.UnaryHandler returns with an error the transaction is aborted, otherwise committed.

func VerifyMigrationVersion added in v0.14.1 

func VerifyMigrationVersion(db *jgorm.DB, v MigrationVersionValidator) error

VerifyMigrationVersion checks the schema_migrations table of the db passed against the ValidVersion function of the given validator, returning an error for an invalid version or a dirty database

Types

type EmptyFieldPathError added in v0.7.0 

type EmptyFieldPathError struct {
}

func (*EmptyFieldPathError) Error added in v0.7.0 

func (e *EmptyFieldPathError) Error() string

type MigrationVersionValidator added in v0.14.1 

type MigrationVersionValidator interface {
	ValidVersion(int64) error
}

MigrationVersionValidator has a function for checking the database version

func MaxVersionFrom added in v0.14.1 

func MaxVersionFrom(path string) (MigrationVersionValidator, error)

MaxVersionFrom returns a MigrationVersionValidator with a target based on the highest numbered migration file detected in the given directory

func VersionExactly added in v0.14.1 

func VersionExactly(version int64) MigrationVersionValidator

VersionExactly returns a MigrationVersionValidator with a specific target version

func VersionRange added in v0.14.1 

func VersionRange(lower, upper int64) MigrationVersionValidator

VersionRange returns a MigrationVersionValidator with a given lower and upper bound

type Transaction added in v0.5.0 

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

Transaction serves as a wrapper around `*gorm.DB` instance. It works as a singleton to prevent an application of creating more than one transaction instance per incoming request.

func FromContext added in v0.5.0 

func FromContext(ctx context.Context) (txn *Transaction, ok bool)

FromContext returns the *Transaction value stored in ctx, if any.

func NewTransaction added in v0.9.0 

func NewTransaction(db *gorm.DB) Transaction

func (*Transaction) AddAfterCommitHook added in v0.7.0 

func (t *Transaction) AddAfterCommitHook(hooks ...func(context.Context))

func (*Transaction) Begin added in v0.5.0 

func (t *Transaction) Begin() *gorm.DB

Begin starts new transaction by calling `*gorm.DB.Begin()` Returns new instance of `*gorm.DB` (error can be checked by `*gorm.DB.Error`)

func (*Transaction) Commit added in v0.5.0 

func (t *Transaction) Commit(ctx context.Context) error

Commit finishes transaction by calling `*gorm.DB.Commit()` Reset current transaction and returns an error if any.

func (*Transaction) Rollback added in v0.5.0 

func (t *Transaction) Rollback() error

Rollback terminates transaction by calling `*gorm.DB.Rollback()` Reset current transaction and returns an error if any.

Source Files

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