[Database] MongoDB (2) 高级查询条件操作符
MongoDB 支持多种复杂的查询方式,能实现大多数 T-SQL 功能,远不是 Key-Value 之类的 NoSQL DB 所能比拟的。
Conditional Operators : $slice //切片
Conditional Operators : $lt <, $lte <=, $gt >, $gte >=
Conditional Operator : $ne //不等于
Conditional Operator : $in //属于
Conditional Operator : $nin //不属于
Conditional Operator : $mod //取模运算
Conditional Operator: $all //全部属于
Conditional Operator : $size //数量
Conditional Operator: $exists //字段存在
Conditional Operator: $type //字段类型
Conditional Operator: $or // 或
Regular Expressions //正则表达式
Value in an Array // 数组中的值
Conditional Operator: $elemMatch //要素符合
Value in an Embedded Object //内嵌对象中的值
Meta operator: $not //不是
Javascript Expressions and $where //
sort() //排序
limit() //限制取数据条数
skip() //跳过一定数值开始取
snapshot() //
count() // 数量
group() //分组
准备数据
In [9]: db
Out[9]: Database(Connection('localhost', 27017), u'test')
In [10]: table = db.table_abeen
In [11]: table
Out[11]: Collection(Database(Connection('localhost', 27017), u'test'), u'table_abeen')
In [12]: table.insert({"name":"abeen", "age":27})
Sun Aug 8 23:14:20 connection accepted from 127.0.0.1:46143 #27
Out[12]: ObjectId('4c5f9cbc421aa90fb9000000')
In [14]: table.insert({"name":"shanshan", "age":22})
Out[14]: ObjectId('4c5f9ccb421aa90fb9000001')
Conditional Operator: $ne (not equal)
//查找name不等于abeen的信息
In [24]: list(table.find({"name":{"$ne":"abeen"}}))
Out[24]:
[{u'_id': ObjectId('4c5f9ccb421aa90fb9000001'),
u'age': 22,
u'name': u'shanshan'},
{u'_id': ObjectId('4c5f9d2d421aa90fb9000002'),
u'age': 22,
u'name': u'shanshan2'},
{u'_id': ObjectId('4c5f9d34421aa90fb9000003'),
u'age': 23,
u'name': u'shanshan3'}]
Conditional Operator: $gt $lt(gt= greater than, lt=less than)
//查找name不等于abeen,并且age大于22的
In [29]: list(table.find({"name": {"$ne": "abeen"}, "age":{"$gt": 22}}))
Out[29]:
[{u'_id': ObjectId('4c5f9d34421aa90fb9000003'),
u'age': 23,
u'name': u'shanshan3'}]
获取子集 $ne $slice
//select "age" from table where name = "abeen"
In [42]: list(table.find({"name": "abeen"}, {"age" : 1}))
Out[42]: [{u'_id': ObjectId('4c5f9cbc421aa90fb9000000'), u'age': 27}]
//get all posts about mongodb without "age"
In [43]: list(table.find({"name": "abeen"}, {"age" : 0}))
Out[43]: [{u'_id': ObjectId('4c5f9cbc421aa90fb9000000'), u'name': u'abeen'}]
//name不等于abeen的"age"信息,取前5条
In [48]: list(table.find({"name": {"$ne":"abeen"}}, {"age":{"$slice":5}}))
//取name信息,从第10条开始取20条
In [54]: list(table.find({}, {"name": {"$slice": [10,20]}}))
//取name信息,从后20条开始取10条
In [55]: list(table.find({}, {"name": {"$slice": [-20,10]}}))
取数值范围
//age大于23的
In [56]: list(table.find({"age":{"$gt":23}}))
Out[56]: [{u'_id': ObjectId('4c5f9cbc421aa90fb9000000'), u'age': 27, u'name': u'abeen'}]
//age小于23的
In [57]: list(table.find({"age":{"$lt":23}}))
Out[57]:
[{u'_id': ObjectId('4c5f9ccb421aa90fb9000001'),
u'age': 22,
u'name': u'shanshan'},
{u'_id': ObjectId('4c5f9d2d421aa90fb9000002'),
u'age': 22,
u'name': u'shanshan2'}]
//age大于等于23的
In [58]: list(table.find({"age":{"$gte":23}}))
Out[58]:
[{u'_id': ObjectId('4c5f9cbc421aa90fb9000000'), u'age': 27, u'name': u'abeen'},
{u'_id': ObjectId('4c5f9d34421aa90fb9000003'),
u'age': 23,
u'name': u'shanshan3'},
{u'_id': ObjectId('4c5fa2ab421aa90fb9000004'),
u'address': u'da zhong si',
u'age': 23,
u'name': u'shanshan3'}]
//age小于等于23的
In [59]: list(table.find({"age":{"$lte":23}}))
Out[59]:
[{u'_id': ObjectId('4c5f9ccb421aa90fb9000001'),
u'age': 22,
u'name': u'shanshan'},
{u'_id': ObjectId('4c5f9d2d421aa90fb9000002'),
u'age': 22,
u'name': u'shanshan2'},
{u'_id': ObjectId('4c5f9d34421aa90fb9000003'),
u'age': 23,
u'name': u'shanshan3'},
{u'_id': ObjectId('4c5fa2ab421aa90fb9000004'),
u'address': u'da zhong si',
u'age': 23,
u'name': u'shanshan3'}]
Conditional Operator: $gt
//22 < age < 25的
In [63]: list(table.find({"age": {"$gt":22, "$lt":25}}))
Out[63]:
[{u'_id': ObjectId('4c5f9d34421aa90fb9000003'),
u'age': 23,
u'name': u'shanshan3'},
{u'_id': ObjectId('4c5fa2ab421aa90fb9000004'),
u'address': u'da zhong si',
u'age': 23,
u'name': u'shanshan3'}]
Conditional Operator : $in
//name在列表["abeen","ab","b"]里面的
In [67]: list(table.find({"name":{"$in":["abeen","ab","b"]}}))
Out[67]: [{u'_id': ObjectId('4c5f9cbc421aa90fb9000000'), u'age': 27, u'name': u'abeen'}]
//name在列表["abeen","ab","b"]里面的,限制取1条数据
In [69]: list(table.find({"name":{"$in":["abeen","ab","b","shanshan"]}}).limit(1))
Out[69]: [{u'_id': ObjectId('4c5f9cbc421aa90fb9000000'), u'age': 27, u'name': u'abeen'}]
Conditional Operator : $nin (not in)
//name不在列表["abeen","ab","b"]里面的
In [70]: list(table.find({"name":{"$nin":["abeen","ab","b"]}}))
Out[70]:
[{u'_id': ObjectId('4c5f9ccb421aa90fb9000001'),
u'age': 22,
u'name': u'shanshan'},
{u'_id': ObjectId('4c5f9d2d421aa90fb9000002'),
u'age': 22,
u'name': u'shanshan2'},
{u'_id': ObjectId('4c5f9d34421aa90fb9000003'),
u'age': 23,
u'name': u'shanshan3'},
{u'_id': ObjectId('4c5fa2ab421aa90fb9000004'),
u'address': u'da zhong si',
u'age': 23,
u'name': u'shanshan3'}]
Conditional Operator: $mod
// 查找age除10模等于1的
In [71]: list(table.find({"age":{"$mod":[10,1]}}))
Conditional Operator: $all
//取name包含所有["abeen","a","b"]的信息
In [77]: list(table.find({"name":{"$all":["abeen","a","b"]}}))
Out[77]:
[{u'_id': ObjectId('4c5facc6421aa90fb9000005'),
u'name': [u'abeen', u'a', u'b', u'e', u'e', u'n']}]
Conditional Operator: $size
//取name元素数和$size数相同的信息
In [81]: list(table.find({"name":{"$size": 6}}))
Out[81]:
[{u'_id': ObjectId('4c5facc6421aa90fb9000005'),
u'name': [u'abeen', u'a', u'b', u'e', u'e', u'n']}]
Conditional Operator: $exists
//取name存在的信息
In [83]: list(table.find({"name":{"$exists": True}}))
Out[83]:
[{u'_id': ObjectId('4c5f9cbc421aa90fb9000000'), u'age': 27, u'name': u'abeen'},
{u'_id': ObjectId('4c5f9ccb421aa90fb9000001'),
u'age': 22,
u'name': u'shanshan'},
{u'_id': ObjectId('4c5f9d2d421aa90fb9000002'),
u'age': 22,
u'name': u'shanshan2'},
{u'_id': ObjectId('4c5f9d34421aa90fb9000003'),
u'age': 23,
u'name': u'shanshan3'},
{u'_id': ObjectId('4c5fa2ab421aa90fb9000004'),
u'address': u'da zhong si',
u'age': 23,
u'name': u'shanshan3'},
{u'_id': ObjectId('4c5facc6421aa90fb9000005'),
u'name': [u'abeen', u'a', u'b', u'e', u'e', u'n']}]
//取name不存在信息
In [84]: list(table.find({"name":{"$exists": False}}))
Out[84]: []
Conditional Operator: $type
//name类型为字符串的
In [88]: list(table.find({"name":{"$type": 2}}))
type对应该类型表如下:
Conditional Operator: $or
//查找name等于abeen或等于shanshan的信息
In [95]: list(table.find({"$or" :[{"name": "abeen"}, {"name":"shanshan"}]}))
Out[95]: []
//查找age等于22,或name等于abeen或等于shanshan的信息
In [96]: list(table.find({"age":22, "$or" :[{"name": "abeen"}, {"name":"shanshan"}]}))
Out[96]: []
Regular Expressions
//利用正则查询
In [114]: list(table.find({"name": {"$regex": r".*ee.*"}}))
Out[114]:
[{u'_id': ObjectId('4c5f9cbc421aa90fb9000000'), u'age': 27, u'name': u'abeen'},
{u'_id': ObjectId('4c5facc6421aa90fb9000005'),
u'name': [u'abeen', u'a', u'b', u'e', u'e', u'n']}]
正则表达式标记:
i: 忽略大小写。
m: 默认为单行处理,此标记表示多行。
x: 扩展。
Conditional Operator: $elemMatch
In [135]: list(table.find( { "age" : {"$elemMatch": {"name": {"$regex": r".*ee.*"},
"age":{"$gt":22}}}}))
Value in an Embedded Object
//查找内部对象信息,
//查找内部对象info的name等于abeen的信息
In [217]: list(table.find({"info.name": "abeen"}))
Out[217]:
[{u'_id': ObjectId('4c5fcd7e421aa90fb9000007'),
u'info': {u'address': u'beijing', u'age': 28, u'name': u'abeen'},
u'name': u'abeen_object'}]
Meta operator: $not
//查询age不在大于23的范围内的信息
In [160]: list(table.find({"age": {"$not":{"$gt": 23}}}))
Out[160]:
[{u'_id': ObjectId('4c5f9ccb421aa90fb9000001'),
u'age': 22,
u'name': u'shanshan'},
{u'_id': ObjectId('4c5f9d2d421aa90fb9000002'),
u'age': 22,
u'name': u'shanshan2'},
{u'_id': ObjectId('4c5f9d34421aa90fb9000003'),
u'age': 23,
u'name': u'shanshan3'},
{u'_id': ObjectId('4c5fa2ab421aa90fb9000004'),
u'address': u'da zhong si',
u'age': 23,
u'name': u'shanshan3'},
{u'_id': ObjectId('4c5facc6421aa90fb9000005'),
u'name': [u'abeen', u'a', u'b', u'e', u'e', u'n']}]
Javascript Expressions and $where
//age大于23的
In [164]: list(table.find({"age": {"$gt":23}}))
Out[164]:
[{u'_id': ObjectId('4c5f9cbc421aa90fb9000000'), u'age': 27, u'name': u'abeen'},
{u'_id': ObjectId('4c5fae95421aa90fb9000006'), u'age': 25, u'name': u''}]
//age大于23的
In [165]: list(table.find({"$where": "this.age > 23"}))
Out[165]:
[{u'_id': ObjectId('4c5f9cbc421aa90fb9000000'), u'age': 27, u'name': u'abeen'},
{u'_id': ObjectId('4c5fae95421aa90fb9000006'), u'age': 25, u'name': u''}]
//skip() limit()
In [204]: result = table.find().skip(2).limit(3)
In [205]: for r in result : print r
{u'age': 22, u'_id': ObjectId('4c5f9d2d421aa90fb9000002'), u'name': u'shanshan2'}
{u'age': 23, u'_id': ObjectId('4c5f9d34421aa90fb9000003'), u'name': u'shanshan3'}
{u'age': 23, u'_id': ObjectId('4c5fa2ab421aa90fb9000004'), u'name': u'shanshan3',
u'address': u'da zhong si'}
更多信息
http://www.mongodb.org/display/DOCS/Advanced+Queries#AdvancedQueries-Introduction