mongoDB query (with array)

user collections에 data가 아래와 같을 때:

  {name:"kim", food:["rice","water" ]}

  {name:"lee", food:["rice","orange" ]}

 

Field Display : _id는 default.

> db.user.find( {name:"kim"}, {food:false, _id:false } )

result: {"name":"kim"}

 

 

array

>  db.user.find( {food:"rice"} )       : array 1depth까지 바로 탐색.

result:  all user 2 line. 

  update array { $push (rightmost),  $pop:1(rightmost),       $pull (remove),  $addToSet(work like set) 

  >  db.user.update( {name:"kim", {food: { $pop:1}} )      

 

 

 

$or,

> db.user.find( { $or:[ { name:"kim"}, {name:"lee"} ] } )

 

$and

 and는 보통 필요가 없다.

> db.user.find( {name:"kim", food:"rice"}  ) ?

result: kim user 1 line. 

$regex, 

> db.user.find(  {name:  {$regex:" ^k"}   } )

result: kim user 1 line.

$exists (=field exists )

> db.user.find(  {name:  {$exists:true}   } )

result: all user 2line

$all,

> db.user.find ( {rice: {$all ["rice","water] }} )

result: kim user 1 line.

$in,  (sql 의 in과 유사)

> db.user.find ( {rice: {$in ["orange","water] }} )

result: all user 2 line.