MongoDB 和 Java 驱动程序：查询中“忽略大小写”

使用MongoDB和Java驱动程序进行查询时，有时我们需要忽略大小写。这在某些情况下非常有用，例如在搜索功能中，我们希望不区分文本的大小写。幸运的是，MongoDB的Java驱动程序提供了一种简单的方法来实现这一点。

java
MongoClient mongoClient = new MongoClient("localhost", 27017);
MongoDatabase database = mongoClient.getDatabase("mydb");
MongoCollection collection = database.getCollection("users");

java
Pattern pattern = Pattern.compile("^john$", Pattern.CASE_INSENSITIVE);

java
BasicDBObject query = new BasicDBObject("name", pattern);
FindIterable result = collection.find(query);

java
for (Document document : result) {
    System.out.println(document);
}

java
import com.mongodb.BasicDBObject;
import com.mongodb.MongoClient;
import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import org.bson.Document;
import java.util.regex.Pattern;
public class IgnoreCaseQueryExample {
    public static void main(String[] args) {
        MongoClient mongoClient = new MongoClient("localhost", 27017);
        MongoDatabase database = mongoClient.getDatabase("mydb");
        MongoCollection collection = database.getCollection("users");
        Pattern pattern = Pattern.compile("^john$", Pattern.CASE_INSENSITIVE);
        BasicDBObject query = new BasicDBObject("name", pattern);
        FindIterable result = collection.find(query);
        for (Document document : result) {
            System.out.println(document);
        }
        mongoClient.close();
    }
}