find除了精确查询外，可以匹配更多的条件；
一、比较操作符
$lt代表<;
$lte代表<=;
$gt代表>;
$gte代表>=;
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | > db.post. find () { "_id" : ObjectId( "54a530c3ff0df3732bac1681" ), "id" : 2, "name" : "joe" , "age" : 30, "sex" : 1, "school" : "marry" } { "_id" : ObjectId( "54a530c3ff0df3732bac1680" ), "id" : 1, "name" : "joe" , "age" : 30, "comments" : [ "test2" , "test9" , "test5" ], "sex" : 1, "school" : "marry" } { "_id" : ObjectId( "54a9700e1b5afd45354fd086" ), "id" : 3, "test3" : 3 } { "_id" : ObjectId( "54a9701c1b5afd45354fd087" ), "id" : 4, "test4" : 4 } { "_id" : ObjectId( "54a970281b5afd45354fd088" ), "id" : 5, "test5" : 5 } { "_id" : ObjectId( "54a970351b5afd45354fd089" ), "id" : 6, "test6" : 6 } { "_id" : ObjectId( "54a970781b5afd45354fd08a" ), "id" : 7, "test7" : 7 } { "_id" : ObjectId( "54a970831b5afd45354fd08b" ), "id" : 8, "test8" : 8 } { "_id" : ObjectId( "54a970901b5afd45354fd08c" ), "id" : 9, "test9" : 9 } { "_id" : ObjectId( "54a9709c1b5afd45354fd08d" ), "id" : 10, "test10" : 10 } > db.post. find ({ "id" :{ "$gte" :5, "$lte" :7}}) { "_id" : ObjectId( "54a970281b5afd45354fd088" ), "id" : 5, "test5" : 5 } { "_id" : ObjectId( "54a970351b5afd45354fd089" ), "id" : 6, "test6" : 6 } { "_id" : ObjectId( "54a970781b5afd45354fd08a" ), "id" : 7, "test7" : 7 } > |
$ne代表不等于:
| 1 2 3 4 5 6 7 8 9 10 11 | > db.post. find ({ "id" :{ "$ne" :8}}) { "_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( "54a970901b5afd45354fd08c" ), "id" : 9, "test9" : 9 } { "_id" : ObjectId( "54a9709c1b5afd45354fd08d" ), "id" : 10, "test10" : 10 } > |
$in可以查询多个键值:
| 1 2 3 4 5 | > db.post. find ({ "id" :{ "$in" :[4,2,8]}}) { "_id" : ObjectId( "54a530c3ff0df3732bac1681" ), "id" : 2, "name" : "joe" , "age" : 30, "sex" : 1, "school" : "marry" } { "_id" : ObjectId( "54a9701c1b5afd45354fd087" ), "id" : 4, "test4" : 4 } { "_id" : ObjectId( "54a970831b5afd45354fd08b" ), "id" : 8, "test8" : 8 } > |
$nin用法：
| 1 2 3 4 5 6 7 8 9 | > db.post. find ({ "id" :{ "$nin" :[4,2,8]}}) { "_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( "54a970281b5afd45354fd088" ), "id" : 5, "test5" : 5 } { "_id" : ObjectId( "54a970351b5afd45354fd089" ), "id" : 6, "test6" : 6 } { "_id" : ObjectId( "54a970781b5afd45354fd08a" ), "id" : 7, "test7" : 7 } { "_id" : ObjectId( "54a970901b5afd45354fd08c" ), "id" : 9, "test9" : 9 } { "_id" : ObjectId( "54a9709c1b5afd45354fd08d" ), "id" : 10, "test10" : 10 } > |
$or的用法：
| 1 2 3 4 5 | > db.post. find ({ "$or" :[{ "sex" :1},{ "id" :5}]}) { "_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( "54a970281b5afd45354fd088" ), "id" : 5, "test5" : 5 } > |
$mod会将查询的值除以第一个给定的值，若余数匹配第二个值，则匹配成功；
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | > db.post. find () { "_id" : ObjectId( "54a530c3ff0df3732bac1681" ), "id" : 2, "name" : "joe" , "age" : 30, "sex" : 1, "school" : "marry" } { "_id" : ObjectId( "54a530c3ff0df3732bac1680" ), "id" : 1, "name" : "joe" , "age" : 30, "comments" : [ "test2" , "test9" , "test5" ], "sex" : 1, "school" : "marry" } { "_id" : ObjectId( "54a9700e1b5afd45354fd086" ), "id" : 3, "test3" : 3 } { "_id" : ObjectId( "54a9701c1b5afd45354fd087" ), "id" : 4, "test4" : 4 } { "_id" : ObjectId( "54a970281b5afd45354fd088" ), "id" : 5, "test5" : 5 } { "_id" : ObjectId( "54a970351b5afd45354fd089" ), "id" : 6, "test6" : 6 } { "_id" : ObjectId( "54a970781b5afd45354fd08a" ), "id" : 7, "test7" : 7 } { "_id" : ObjectId( "54a970831b5afd45354fd08b" ), "id" : 8, "test8" : 8 } { "_id" : ObjectId( "54a970901b5afd45354fd08c" ), "id" : 9, "test9" : 9 } { "_id" : ObjectId( "54a9709c1b5afd45354fd08d" ), "id" : 10, "test10" : 10 } { "_id" : ObjectId( "54aa8a90652d8bdfa0566d34" ), "id" : 11, "test10" : 11 } > db.post. find ({ "id" :{$mod:[5,1]}}) { "_id" : ObjectId( "54a530c3ff0df3732bac1680" ), "id" : 1, "name" : "joe" , "age" : 30, "comments" : [ "test2" , "test9" , "test5" ], "sex" : 1, "school" : "marry" } { "_id" : ObjectId( "54a970351b5afd45354fd089" ), "id" : 6, "test6" : 6 } { "_id" : ObjectId( "54aa8a90652d8bdfa0566d34" ), "id" : 11, "test10" : 11 } > |