mongo通find来查找文档。可以执行精确匹配和模糊匹配。
2. 模糊匹配
2.1比较
> $gt , >= $gte, < $lt, <= $lte, != $ne
> db.tianyc02.find()
{ "_id" : ObjectId("50ea6eba12729d90ce6e3423"), "name" : "xttt", "age" : 111 }{ "_id" : ObjectId("50ea6eba12729d90ce6e3424"), "name" : "xttt", "age" : 222 }{ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "name" : "xtt", "age" : 11 }{ "_id" : ObjectId("50ea6b7312729d90ce6e341c"), "name" : "xtt", "age" : 22 }> db.tianyc02.find({age:{$lt:100}}){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "name" : "xtt", "age" : 11 }{ "_id" : ObjectId("50ea6b7312729d90ce6e341c"), "name" : "xtt", "age" : 22 }> db.tianyc02.find({age:{$lt:100,$gt:20}}){ "_id" : ObjectId("50ea6b7312729d90ce6e341c"), "name" : "xtt", "age" : 22 }> db.tianyc02.find({age:{$ne:11}}){ "_id" : ObjectId("50ea6eba12729d90ce6e3423"), "name" : "xttt", "age" : 111 }{ "_id" : ObjectId("50ea6eba12729d90ce6e3424"), "name" : "xttt", "age" : 222 }{ "_id" : ObjectId("50ea6b7312729d90ce6e341c"), "name" : "xtt", "age" : 22 }2.2 $in & $nin
> db.tianyc02.find()
{ "_id" : ObjectId("50ea6eba12729d90ce6e3423"), "name" : "xttt", "age" : 111 }{ "_id" : ObjectId("50ea6eba12729d90ce6e3424"), "name" : "xttt", "age" : 222 }{ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "name" : "xtt", "age" : 11 }{ "_id" : ObjectId("50ea6b7312729d90ce6e341c"), "name" : "xtt", "age" : 22 }> db.tianyc02.find({age:{$in:[11,22]}}){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "name" : "xtt", "age" : 11 }{ "_id" : ObjectId("50ea6b7312729d90ce6e341c"), "name" : "xtt", "age" : 22 }> db.tianyc02.find({age:{$nin:[11,22]}}){ "_id" : ObjectId("50ea6eba12729d90ce6e3423"), "name" : "xttt", "age" : 111 }{ "_id" : ObjectId("50ea6eba12729d90ce6e3424"), "name" : "xttt", "age" : 222 }2.3 $or
> db.tianyc02.find({$or:[{age:11},{age:22}]})
{ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "name" : "xtt", "age" : 11 }{ "_id" : ObjectId("50ea6b7312729d90ce6e341c"), "name" : "xtt", "age" : 22 }> db.tianyc02.find({$or:[{age:11},{name:'xttt'}]}){ "_id" : ObjectId("50ea6eba12729d90ce6e3423"), "name" : "xttt", "age" : 111 }{ "_id" : ObjectId("50ea6eba12729d90ce6e3424"), "name" : "xttt", "age" : 222 }{ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "name" : "xtt", "age" : 11 }2.4 $not
> db.tianyc02.find({age:{$mod:[11,0]}})
{ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "name" : "xtt", "age" : 11 }{ "_id" : ObjectId("50ea6b7312729d90ce6e341c"), "name" : "xtt", "age" : 22 }> db.tianyc02.find({age:{$not:{$mod:[11,0]}}}){ "_id" : ObjectId("50ea6eba12729d90ce6e3423"), "name" : "xttt", "age" : 111 }{ "_id" : ObjectId("50ea6eba12729d90ce6e3424"), "name" : "xttt", "age" : 222 }$mod会将查询的值除以第一个给定的值，若余数等于第二个给定的值，则返回该结果。
$not与正则表达式联合使用时极为有效，用来查找那些与特定模式不匹配的文档。