mirror of
https://github.com/golang/go
synced 2024-11-26 20:41:24 -07:00
e24977d231
The next CL will remove the -G flag, effectively hard-coding it to its current default (-G=3). Change-Id: Ib4743b529206928f9f1cca9fdb19989728327831 Reviewed-on: https://go-review.googlesource.com/c/go/+/388534 Reviewed-by: Keith Randall <khr@golang.org> Trust: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
75 lines
1.4 KiB
Go
75 lines
1.4 KiB
Go
// compile
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// Copyright 2021 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package main
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import (
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"database/sql"
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)
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// Collection generic interface which things can be added to.
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type Collection[T any] interface {
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Add(T)
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}
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// Slice generic slice implementation of a Collection
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type Slice[T any] []*T
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func (s *Slice[T]) Add(t *T) {
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*s = append(*s, t)
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}
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type Scanner interface {
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Scan(...interface{}) error
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}
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type Mapper[T any] func(s Scanner, t T) error
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type Repository[T any] struct {
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db *sql.DB
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}
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func (r *Repository[T]) scan(rows *sql.Rows, m Mapper[*T], c Collection[*T]) error {
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for rows.Next() {
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t := new(T)
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if err := m(rows, t); err != nil {
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return err
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}
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c.Add(t)
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}
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return rows.Err()
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}
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func (r *Repository[T]) query(query string, m Mapper[*T], c Collection[*T]) error {
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rows, err := r.db.Query(query)
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if err != nil {
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return err
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}
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if err := r.scan(rows, m, c); err != nil {
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rows.Close()
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return err
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}
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return rows.Close()
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}
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type Actor struct {
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ActorID uint16
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FirstName string
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LastName string
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}
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type ActorRepository struct {
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r Repository[Actor]
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}
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func (ActorRepository) scan(s Scanner, a *Actor) error {
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return s.Scan(&a.ActorID, &a.FirstName, &a.LastName)
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}
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func (r *ActorRepository) SelectAll(c Collection[*Actor]) error {
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return r.r.query("SELECT `actor_id`, `first_name`, `last_name` FROM `actor` LIMIT 10", r.scan, c)
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}
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