Papergres

Papergres is an ultra lightweight micro-ORM written in golang for the postgres database server. The library provides easy ways to execute queries, insert data and sql logging.

This is a wrapper around the general purpose extensions library sqlx by jmoiron. The core postgres driver used is pq.

Papergres is built and used at Paperchain. Special thanks to [Weston Dorsey(https://github.com/wdorsey), for sparking up the project.

Install

go get -u github.com/Paperchain/papergres

API Documentation

Full API documentation can be found on godoc

Contributors

We're open to and looking for open-source contributors to help make this library more robust

Usage

The simplest way to execute a query returning a single object is

// Set up your connection object
conn := NewConnection("postgres://postgres:postgres@localhost:5432/paperchain", "papergres_tests", SSLDisable)
db := conn.NewDatabase()

// Write a query in a single line
var book Book
res := db.Query("SELECT * FROM paper.book WHERE book_id = $1 LIMIT 1;", 777).ExecSingle(&book)

To retrieve a list of rows and hydrate it into a list of object

var books []book
res := db.Query("SELECT * FROM paper.book WHERE book_id > 10 LIMIT 1;", 777).ExecAll(&books)

To insert a record into a table

// Create a struct and specify database column names via the "db" struct tag
type Book struct {
	BookId    PrimaryKey `db:"book_id"`
	Title     string     `db:"title"`
	Author    string     `db:"author"`
	CreatedAt time.Time  `db:"created_at"`
	CreatedBy string     `db:"created_by"`
}

// Instantiate your struct
book := &Book{
	Title:     "The Martian",
	Author:    "Andy Weir",
	CreatedAt: time.Now(),
	CreatedBy: "TestInsert",
}

// Perform an insert using papergres
res := db.Insert(book)
if res.Err != nil {
		log.Fatalln(res.Err.Error())
}
    
// Retrieve the inserted ID from the primary key
bookid := res.LastInsertId.ID

// To insert into a specific schema other than the public
schema := db.Schema("my_schema")
res := schema.Insert(book)

// To insert multiple
res, err := schema.InsertAll(books)

Logging

The library provides an logging interface that needs to implemented

// Instantiate your logged in your application's bootstrap
Log = &testLogger{}

// The logger interface that needs to be implemented. This is available in papergres.go
type Logger interface {
	Info(args ...interface{})
	Infof(format string, args ...interface{})
	Debug(args ...interface{})
	Debugf(format string, args ...interface{})
}

// For example, you can set your logger with something like this
type testLogger struct{}

func (t *testLogger) Info(args ...interface{}) {
	if debug {
		fmt.Println(args...)
	}
}
func (t *testLogger) Infof(format string, args ...interface{}) {
	if debug {
		fmt.Printf(format, args...)
	}
}
func (t *testLogger) Debug(args ...interface{}) {
	if debug {
		fmt.Println(args...)
	}
}
func (t *testLogger) Debugf(format string, args ...interface{}) {
	if debug {
		fmt.Printf(format, args...)
	}
}

Example of the sql logging