update

'$set': {

"options":{

"A":"choice A stands for",

"B":"choice B stands for",

"C":"choice C stands for",

"D":"choice D stands for",

}

}

 

find

 $and:[{html:/答案/},{html:/回复/}]

$or:[{html:/答案/},{title:/测试/}]

find words contains both elements "text" and "here" or either of them:

db.things.find( { words: { $all: [ "text", "here" ] } } );

or

db.things.find( { words: { $in: [ "text", "here" ] } } );