我是pg-promise的作者;）
con.task(t => { const a = post => t.any('SELECt * FROM comment WHERe idPost = $1', post.id) .then(comments => { post.comments = comments; return post; }); return t.map('SELECt *, avatar FROM post, users WHERe user = $1 AND user = alias ORDER BY time DESC LIMIT 10 OFFSET $2', [username, pos], a) .then(t.batch);}) .then(posts => { res.send(posts); }) .catch(error => { console.log(error); });更新
如果您不想一路使用JSON查询方法，那么以下方法将比原始解决方案更好地扩展，因为我们将所有子查询连接起来，然后将它们作为一个查询执行：
con.task(async t => { const posts = await t.any('SELECt *, avatar FROM post, users WHERe user = $1 AND user = alias ORDER BY time DESC LIMIT 10 OFFSET $2', [username, pos]); const a = post => ({query: 'SELECt * FROM comment WHERe idPost = ${id}', values: post}); const queries = pgp.helpers.concat(posts.map(a)); await t.multi(queries) .then(comments => { posts.forEach((p, index) => { p.comments = comments[index]; }); }); return posts;}) .then(posts => { res.send(posts); }) .catch(error => { console.log(error); });查看API：
- helpers.concat
- 多数据库
