To create atextindex, use thedb.collection.createIndex()method. To index a field that contains a string or an array of string elements, include the field and specify the string literal"text"in the index document, as in the following example: ...
$text Performs text search. $where satisfy a JavaScript expression. Array $all contain all elements specified in the query. $elemMatch $size 元素个数 comments $comment Adds a comment to a query predicate. associates a comment to any expression taking a query predicate. for example: db.collecti...
The following query filter finds all documents wherescoresarray contains the value75, and thenameisGreg Powell: { $and: [ { scores: 75, name: "Greg Powell" } ] } The query returns the following document: { "_id": { "$oid":"5a9427648b0beebeb69579cf" }, ...
QMap<QString, DBColumnProperty> DBManager::GetDBColumnPro(QString qstrTableName) { QSqlQuery query(*db); QString strSQl = QString("select * from information_schema.columns where table_name= '%1' and table_schema='public'").arg(qstrTableName); query.prepare(strSQl); if (query.exec())...
https://docs.mongodb.com/manual/tutorial/text-search-in-aggregation/ 如同内置了多语言分词机制 在一个操作频繁的集合上创建全文本检索可能回到导致MongoDB过载,应该是离线状态下创建全文检索。 创建全文检索可能会导致内存不够用。 测试数据: db.textIndexTest.insert({author:"杜甫",title:"绝句",article:"两...
一些常见的数据格式例如:JSON、XML、简单的键/值对。 储存在MongoDB中的文档是一种类JSON格式,为了得到更高的效率,使用了一种二进制表现形式且被称为BSON的格式。目标是使数据更紧凑和合理以便于扫描。 客户端序列化数据成BSON传送至数据库中,数据是以BSON格式被存储的。因此,读取数据的时候,数据库只需做很小的...
Text Score Metadata Sort 注意 $text提供自管理(非 Atlas)部署的文本查询功能。对于托管在 MongoDB Atlas 上的数据,MongoDB 提供了一种改进的全文查询解决方案Atlas Search。 对于包含$text的管道,您可以使用{ $meta: "textScore" }表达式按相关性分数降序排序。在{ <sort-key> }文档中,将{ $meta: "textSco...
keySet.contains(fieldName)) Some(doc.getBoolean(fieldName)) else None } def mgoGetDateOrNone(doc: Document, fieldName: String) = { if (doc.keySet.contains(fieldName)) Some(doc.getDate(fieldName)) else None } def mgoGetBlobOrNone(doc: Document, fieldName: String) = { if (doc....
MongoCollection<Document>collection=null;if(!mongoTemplate.getCollectionNames().contains("MyNewCollection")){collection=mongoTemplate.createCollection("MyNewCollection");}mongoTemplate.dropCollection("MyNewCollection"); getCollectionNames:返回一组集合名称。
db.student.createIndex({remarks:"text"}) Consider the following query which returns all documents in the student collection where any field contains the stringnice. Further, the$caseSensitiveoperator is given a true value to check the case insensitivity of the stringnice. ...