https://github.com/olegfomenko/pg-dao

Data Access Object for PostgreSQL for Distributed Lab projects.
https://github.com/olegfomenko/pg-dao

distributed-lab go postgresql

Last synced: 9 days ago
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Data Access Object for PostgreSQL for Distributed Lab projects.

• Host: GitHub
• URL: https://github.com/olegfomenko/pg-dao
• Owner: olegfomenko
• Created: 2021-10-08T12:28:51.000Z (about 3 years ago)
• Default Branch: master
• Last Pushed: 2024-02-04T13:38:14.000Z (10 months ago)
• Last Synced: 2024-06-20T16:32:08.992Z (5 months ago)
• Topics: distributed-lab, go, postgresql
• Language: Go
• Homepage:
• Size: 1.58 MB
• Stars: 2
• Watchers: 2
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# pg-dao

Data Access Object for PostgreSQL for Distributed Lab projects.

## Usage

```go

package main

import (

	"errors"

	pg "github.com/olegfomenko/pg-dao"

	"gitlab.com/distributed_lab/kit/kv"

)

type Entry struct {

	Id   int64  `db:"id" structs:"-"`

	Name string `db:"name" structs:"name"`

}

func main() {

	// Loading config

	cfg := config.New(kv.MustFromEnv())

	// Creating DAO instance for table "entries"

	dao := pg.NewDAO(cfg.DB(), "entries")

	// Saving record

	// id - saved entry index

	id, err := dao.Create(Entry{

		Name: "First Entry",

	})

	// Cloning DAO for new session

	dao = dao.Clone()

	// Cleaning queries in DAO in current session

	dao = dao.New()

	// Updating entry

	err = dao.UpdateWhereID(id).UpdateColumn("name", "New First Entry").Update()

	// Getting entry by id

	var entry Entry

	// if ok is false - there is no entry with provided id

	ok, err := dao.New().FilterByID(id).Get(&entry)

	// Getting entry by field

	ok, err = dao.New().FilterByColumn("name", "New First Entry").Get(&entry)

	// Deleting entry

	err = dao.New().DeleteWhereID(id).Delete()

	// Creating transaction

	err = dao.Clone().TransactionSerializable(

		func(q pg.DAO) error {

			ok, err := q.FilterByID(id).Get(&entry)

			if err != nil {

				// rollback transaction

				return err

			}

			if !ok {

				// entry does not exist

				return errors.New("not found")

			}

			err = q.New().UpdateWhereID(id).UpdateColumn("name", "Updated First Entry").Update()

			if err != nil {

				// rollback transaction

				return err

			}

			// commit transaction

			return nil

		},

	)

}

```