scany

Core Purpose

scany is a scanning utility designed to map database rows into Go structs, maps, and primitive types. It eliminates the need for manual row iteration and column-by-column scanning.

Key Features

• Custom database column names via struct tags.
• Support for nested or embedded structs.
• Support for NULL values and custom types.
• Ability to omit specific struct fields.
• Support for destination types like maps and Go primitives.
• Ability to override default settings.

Important Distinctions

• Not an ORM: scany only works in one direction (Database $\rightarrow$ Go objects). It cannot build queries based on Go objects.
• No Relation Management: It does not handle relationships between objects (e.g., one-to-many or many-to-many).

To use scany in your Go project, install the v2 package using go get:

go get github.com/georgysavva/scany/v2

If you are using the pgx library's native interface (e.g., pgxpool), use the pgxscan package. This provides the same scanning capabilities as sqlscan but is optimized for the pgx driver's native types and interfaces.

package main

import (
	"context"

	"github.com/jackc/pgx/v5/pgxpool"

	"github.com/georgysavva/scany/v2/pgxscan"
)

type User struct {
	ID    string
	Name  string
	Email string
	Age   int
}

func main() {
	ctx := context.Background()
	db, _ := pgxpool.New(ctx, "example-connection-url")

	var users []*User
	pgxscan.Select(ctx, db, &users, `SELECT id, name, email, age FROM users`)
	// users variable now contains data from all rows.
}

To scan database rows into Go structs using the standard database/sql library, use the sqlscan package. The sqlscan.Select function allows you to execute a query and automatically populate a slice of structs or a single struct without manual row iteration.

package main

import (
	"context"
	"database/sql"

	"github.com/georgysavva/scany/v2/sqlscan"
)

type User struct {
	ID    string
	Name  string
	Email string
	Age   int
}

func main() {
	ctx := context.Background()
	db, _ := sql.Open("postgres", "example-connection-url")

	var users []*User
	sqlscan.Select(ctx, db, &users, `SELECT id, name, email, age FROM users`)
	// users variable now contains data from all rows.
}