MongoDB数据库的updateapi接口使用说明

java客户端例子： 

set = conn.prepareStatement(querysql+fromsql).executeQuery() ;

while(set.next()){

DBObject q = new BasicDBObject().append("T", "a")

.append("CI", String.valueOf(set.getInt(1)))

.append("AI", String.valueOf(set.getInt(3)));

DBObject o = new BasicDBObject().append("$set",

new BasicDBObject().append("CN", set.getString(2))

.append("AN", set.getString(4)).append("S", set.getString(5)));

Mongodb.getDB("yqflog").getCollection("info").update(q, o , true , true );

}

mongodb的java客户端的api： 

    /**

     * calls {@link DBCollection#update(com.mongodb.DBObject, com.mongodb.DBObject, boolean, boolean, com.mongodb.WriteConcern)} with default WriteConcern.

     * @param q search query for old object to update

     * @param o object with which to update q

     * @param upsert if the database should create the element if it does not exist

     * @param multi if the update should be applied to all objects matching (db version 1.1.3 and above)

     *              See http://www.mongodb.org/display/DOCS/Atomic+Operations

     * @return

     * @throws MongoException

     * @dochub update

     */

    public WriteResult update( DBObject q , DBObject o , boolean upsert , boolean multi )

        throws MongoException {

        return update( q , o , upsert , multi , getWriteConcern() );

    }

shell命令行： 

db.collection.update( criteria, objNew, upsert, multi )

Arguments:

criteria - query which selects the record to update;

objNew - updated object or $ operators (e.g., $inc) which manipulate the object

upsert - if this should be an "upsert" operation; that is, if the record(s) do not exist, insert one. Upsert only inserts a single document.

multi - indicates if all documents matching criteria should be updated rather than just one. Can be useful with the $ operators below.

$options 操作说明： 

实例中使用了$set，否则就会丢失原有值；

increments field by the number value if field is present in the object, otherwise sets field to the number value. This can also be used to decrement by using a negative value.

sets field to value. All datatypes are supported with $set.

Deletes a given field. v1.3+