MongoDB Simple Joins

1const simpleJoin1 = await CarModel.aggregate()
2  .lookup({
3    from: 'patches',
4    localField: 'homePatch',
5    foreignField: '_id',
6    as: 'homePatch',
7  })
8  .unwind('homePatch')
9  .match({
10    'homePatch.code': 'PT',
11    'homePatch.name': 'Portugal',
12  });
13
14const simpleJoin2 = await CarModel.aggregate()
15  .lookup({
16    from: 'patches',
17    let: { carHomePatch: '$homePatch' },
18    pipeline: [{ $match: { $expr: { $and: [{ $eq: ['$code', 'PT'] }, { $eq: ['$name', 'Portugal'] }, { $eq: ['$$carHomePatch', '$_id'] }] } } }],
19    as: 'homePatch',
20  })
21  .unwind('homePatch');