norm

norm

norm is a Golang DB layer generator. It generates code that doesn't make any assumptions about the intermediate model structs. It can bind to user provided structs, or generate code that doesn't depend on these. You write SQL, with some comment annotations. These annotations are used to generate the Golang code.

Example

Suppose you have the following SQL query which selects a given user from a users table.

-- !read GetUserListNoModel
-- !input limit int
-- !input offset int
-- !output ID int
-- !output Email *string
-- !doc Retrieves all emails from the users table
SELECT id, email
FROM users
LIMIT $1
OFFSET $2

norm will generate the following API for the above declaration. Note that it allows you to do a custom bind by generating low-level scanning code. In addition, it provides an optional convenience method that returns a wrapper struct for the output.

type GetUserListNoModelResult struct {
	stmt *sql.Stmt
	rows *sql.Rows
}

func (res GetUserListNoModelResult) Next() bool {
	return res.rows.Next()
}

func (res GetUserListNoModelResult) Scan(ID *int, Email **string) error {
	return res.rows.Scan(ID, Email)
}

func (res GetUserListNoModelResult) Close() {
	if res.rows != nil {
		res.rows.Close()
	}
	if res.stmt != nil {
		res.stmt.Close()
	}
}

// Retrieves all emails from the users table
func GetUserListNoModelScan(db *sql.DB, limit int, offset int) (*GetUserListNoModelResult, error) {
	result := GetUserListNoModelResult{}
	var err error
	result.stmt, err = db.Prepare(`SELECT id, email
FROM users
LIMIT $1
OFFSET $2`)
	if err != nil {
		return nil, err
	}
	result.rows, err = result.stmt.Query(limit, offset)
	if err != nil {
		defer result.stmt.Close()
		return nil, err
	}
	return &result, nil
}

type GetUserListNoModelOutput struct {
	ID    int
	Email *string
}

func GetUserListNoModel(db *sql.DB, limit int, offset int) ([]GetUserListNoModelOutput, error) {
	res, err := GetUserListNoModelScan(db, limit, offset)
	if err != nil {
		return nil, err
	}
	defer res.Close()
	var ret []GetUserListNoModelOutput
	for res.Next() {
		var o GetUserListNoModelOutput
		if err := res.Scan(&o.ID, &o.Email); err != nil {
			return ret, err
		}
		ret = append(ret, o)
	}
	return ret, nil
}