snapshot of https://github.com/ThreeDotsLabs/watermill.git (master, 2026-09-15; blobs > 131072B omitted)

_examples/real-world-examples/server-sent-events/server/posts_storage.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"time"
+
+	"github.com/go-sql-driver/mysql"
+)
+
+type PostsStorage struct {
+	db *sql.DB
+}
+
+func NewPostsStorage() PostsStorage {
+	conf := mysql.NewConfig()
+	conf.Net = "tcp"
+	conf.User = "root"
+	conf.Addr = "mysql"
+	conf.DBName = "example"
+
+	db, err := sql.Open("mysql", conf.FormatDSN())
+	if err != nil {
+		panic(err)
+	}
+
+	for {
+		err = db.Ping()
+		if err == nil {
+			break
+		} else {
+			fmt.Println("Could not connect to MySQL, retrying...")
+			time.Sleep(time.Second * 3)
+		}
+	}
+
+	return PostsStorage{
+		db: db,
+	}
+}
+
+func (s PostsStorage) ByID(ctx context.Context, id string) (Post, error) {
+	query := "SELECT title, content, author FROM posts WHERE id=?"
+	row := s.db.QueryRowContext(ctx, query, id)
+
+	var title, content, author string
+	err := row.Scan(&title, &content, &author)
+	if err != nil {
+		return Post{}, err
+	}
+
+	return NewPost(id, title, content, author), nil
+}
+
+func (s PostsStorage) Add(ctx context.Context, post Post) error {
+	query := "INSERT INTO posts (id, title, content, author) VALUES (?, ?, ?, ?)"
+	_, err := s.db.ExecContext(ctx, query, post.ID, post.Title, post.Content, post.Author)
+	return err
+}
+
+func (s PostsStorage) Update(ctx context.Context, post Post) error {
+	query := "UPDATE posts SET title=?, content=?, author=? WHERE id=?"
+	_, err := s.db.ExecContext(ctx, query, post.Title, post.Content, post.Author, post.ID)
+	return err
+}