在 MongoDB Java 驱动程序中创建查询

Question

我有一个包含具有以下字段的文档的集合：

description
state
field_num

我想 return 游标到满足以下条件的所有文档：

有地位"complete"
和 field_num 大于 100
并且他们的描述不包含 "abc" 模式？

这个查询是否正确？

DBObject query = new BasicDBObject("$gte",99)
    .append("status","complete")
    .append("description", new BasicDBObject("$not", ".*abc")))

DBCursor cursor = collection.find("collection name", query, projection)

Answer 1

这个查询：

have status "complete"

and field_num greater than 100

and that their description does not contain "abc" pattern?

...可以表示为：

Bson query =
        // where field_num > 100
        new BasicDBObject("field_num", new BasicDBObject("$gte", 100))

        // where status is ' complete'
        .append("status", new BasicDBObject("$eq", "complete"))

        // where description does not contain 'abc' 
        // note: this uses inverse matching since the $not operator
        // is not allowed with the $regex operator
        .append("description", new BasicDBObject("$regex", "^((?!abc).)*$"));

在 Java 驱动程序 > 3.0 的版本中，这也可以更简单地表示为：

Bson query= Filters.and(
        Filters.gt("field_num", 100),
        Filters.eq("status", "complete"),
        Filters.regex("description", "^((?!abc).)*$")
);

查询执行如下：

MongoClient mongoClient = ...;

MongoCollection<Document> collection = mongoClient.getDatabase("...")
    .getCollection("...");

collection.find(query)

在 MongoDB Java 驱动程序中创建查询

Creating query in MongoDB Java driver

java

mongodb

mongodb-query

mongodb-java