"MongoDB Learning note 17" MongoDB query: Array query in Find

Tag:mongodb   find    array    

Db.post.find ()    {  "_id"  : objectid ("54a530c3ff0df3732bac1681"),  "id"   : 2,  "name"  :  "Joe",  "age"  : 30,  "sex"  : 1,  "school"  :  "Marry"  }    {  "_id"  : objectid ("54a530c3ff0df3732bac1680 "), " id " : 1, " name " : " Joe ", " age " : 30, " comments " :  [  "Test2",  "Test9",  "test5"  ],  "Sex"  : 1,  "school"  :  " Marry " }    { " _id " : objectid (" 54a9700e1b5afd45354fd086 "), " id "  : 3,  "Test3"  : 3 }    {  "_id"  : objectid (" 54a9701c1b5afd45354fd087 "), " id " : 4, " test4 " : 4 }     {  "_id"  : objectid ("54a970281b5afd45354fd088"),  "id"  : 5,  "test5"  :  5 }    {  "_id"  : objectid ("54a970351b5afd45354fd089"),  "id"  : 6,   "Test6"  : 6 }    {  "_id"  : objectid (" 54a970781b5afd45354fd08a "), " id " : 7, " test7 " : 7 }     {  "_id"  : objectid ("54a970831b5afd45354fd08b"),  "id"  : 8,  "test8"  :  8 }    {  "_id"  : objectid ("54a970901b5afd45354fd08c"),  "id"  : 9,  "Test9"  : 9 }    {  "_id"  : objectid (" 54a9709c1b5afd45354fd08d "), " id " : 10, " test10 " : 10 }     {  "_id"  : objectid ("54aa8a90652d8bdfa0566d34"),  "id"  : 11,  "test10"  : 11 }    {  "_id"  : objectid ("54aa97b894dcf31069b590ca"),   "id"  : 12,  "fruit"  : [  "Apple",  "banana",  "peach"  ] }    {  "_id"  :  objectid ("54AA97D794DCF31069B590CB"),  "id"  : 13,  "fruit"  : [  "apple",   "Kumquat",  "Orange"  ] }    {  "_id"  : objectid (" 54aa97f294dcf31069b590cc "), " id " : 14, " fruit " : [ " cherry ", " banana ",   "Apple"  ] }    >

One, $all to match a set of elements in an array

> db.post.find ({"fruit": {$all: ["Apple", "Banana"]}}) {"_id": ObjectId ("54aa97b894dcf31069b590ca"), "id": "Frui" T ": [" apple "," banana "," peach "]} {" _id ": ObjectId (" 54aa97f294dcf31069b590cc ")," id ": +," fruit ": [" Cherry ", "Banana", "Apple"]} >

You can see the order of Apple and banana is not related;

Second, $size to query the matching array length;

> db.post.find ({},{"id": 1, "fruit": 1, "_id": 0})    {  "id"  : 2 }     {  "id"  : 1 }    {  "id"  : 3 }     {  "id"  : 4 }    {  "id"  : 5  }    {  "id"  : 6 }    {  "id"  :  7 }    {  "id"  : 8 }    {  "id"  : 9 }    {  "id"  : 10 }    {  " ID " : 11 }    { " id " : 12, " fruit " : [ " Apple ", " banana ", " peach " ] }    { " id " : 13, " Fruit " : [ " apple ", " Kumquat ", " Orange ", " fruit01 " ] }     {  }     >> db.post.find ({"fruit": {$size: 3})    {  "_id"  :  ObjectId ("54aa97b894dcf31069b590ca"),  "id"  : 12,  "fruit"  : [  "apple",  "Banana",  "peach"  ] }    >

Third, $slice operator

> Db.post.find ({"id": +}) {"_id": ObjectId ("54AA97D794DCF31069B590CB"), "id": +, "fruit": ["apple", "Kumquat", "Orange", "fruit01"]} >

Returns the first two values of an array

> Db.post.find ({"id": 13},{"fruit": {$slice: 2}}) {"_id": ObjectId ("54AA97D794DCF31069B590CB"), "id": "Fruit":    ["Apple", "Kumquat"]} >

Returns the latter two values of an array

> Db.post.find ({"id": 13},{"fruit": {$slice: -2}}) {"_id": ObjectId ("54AA97D794DCF31069B590CB"), "id": "Fruit":    ["Orange", "fruit01"]} >

Returns the two values in the middle of the array

> Db.post.find ({"id": 13},{"fruit": {$slice: [up]}}) {"_id": ObjectId ("54AA97D794DCF31069B590CB"), "id": "Fruit ": [" Kumquat "," Orange "]}

Four, using the array of the following table query

> Db.post.find ({"fruit.3": "fruit01"}) {"_id": ObjectId ("54AA97D794DCF31069B590CB"), "id": +, "fruit": ["Apple", "K Umquat "," Orange "," fruit01 "]}>

This article is from the "Margin with Wish" blog, please be sure to keep this source http://281816327.blog.51cto.com/907015/1599470

"MongoDB Learning note 17" MongoDB query: Array query in Find