'category': 'Legislature',
    'updated': datetime.datetime(2010, 3, 19, 15, 32, 22, 107000),
    'byline': None,
    'tags': {
        'party': ['Peter Hoekstra', 'Virg Bernero', 'Alma Smith', 'Mike Bouchard', 'Tom George', 'Rick Snyder'],
        'geography': ['Michigan', 'United States', 'North America']
    'headline': '2 Mich. gubernatorial candidates speak to students',
    'text': [
        'BEVERLY HILLS, Mich. (AP) \u2014 Two Democratic and Republican gubernatorial candidates found common ground while speaking to private school students in suburban Detroit',
        "Democratic House Speaker state Rep. Andy Dillon and Republican U.S. Rep. Pete Hoekstra said Friday a more business-friendly government can help reduce Michigan's nation-leading unemployment rate.",
        "The candidates were invited to Detroit Country Day Upper School in Beverly Hills to offer ideas for Michigan's future.",
        'Besides Dillon, the Democratic field includes Lansing Mayor Virg Bernero and state Rep. Alma Wheeler Smith. Other Republicans running are Oakland County Sheriff Mike Bouchard, Attorney General Mike Cox, state Sen. Tom George and Ann Arbor business leader Rick Snyder.',
        'Former Republican U.S. Rep. Joe Schwarz is considering running as an independent.'
    'dateline': 'BEVERLY HILLS, Mich.',
    'published': datetime.datetime(2010, 3, 19, 8, 0, 31),
    'keywords': "Governor's Race",
    '_id': ObjectId('4ba39721e0e16cb25fadbb40'),
    'article_id': 'urn:publicid:ap.org:0611e36fb084458aa620c0187999db7e',
    'slug': "BC-MI--Governor's Race,2nd Ld-Writethr"

少なくとも1つのgeographyタグを持つすべての記事を検索するクエリを作成する場合、どうすればよいですか? db.articles.find(\ {'tags': 'geography'})を書いてみましたが、うまくいかないようです。 また、検索パラメーターを「tags.geography」に変更することも考えましたが、検索述語が何であるかを理解する時間の悪魔がいます。

1 Answer



db.articles.find({tags.geography : {$exists : true}})

存在し、空の場合(つまり、 "" geography ":[]`)、 `geography_size`フィールドまたは何かを追加して、実行する必要があります。

db.articles.find({tags.geography_size : {$gte : 1}})