mongodb 高级查询详解(2)
1.查询和投影操作符
1.1比较操作符
$eq
匹配字段值等于指定值的文档
{ <field>: { $eq: <value> } }
$gt
匹配字段值大于指定值的文档
{ <field>: { $gt: <value> } }
$gte
匹配字段值大于等于指定值的文档
{ <field>: { $gte: <value> } }
$lt
匹配字段值小于指定值的文档
{ <field>: { $gte: <value> } }
$lte
匹配字段值小于等于指定值的文档
{ <field>: { $lte: <value> } }
$ne
匹配字段值不等于指定值的文档，包括没有这个字段的文档
{ <field>: { $ne: <value> } }
$in
匹配字段值等于指定数组中的任何值
{ field: { $in: [<value1>, <value2>, ... <valueN> ] } }
字段值为数组类型时，数组中至少有一个元素在指定数组中
{ _id: 1, item: "abc", qty: 10, tags: [ "school", "clothing" ], sale: false }
db.inventory.update(
{ tags: { $in: ["appliances", "school"] } },
{ $set: { sale:true } }
)
sale值被成功改为true
$nin
字段值不在指定数组或者不存在
{ field: { $nin: [ <value1>, <value2> ... <valueN> ]} }
字段值为数组类型时，数组中没有一个元素与指定数组中元素相等
1.2逻辑操作符
$or
文档至少满足其中的一个表达式
{ $or: [ { <expression1> }, { <expression2> }, ... , { <expressionN> } ] }
$and
{ $and: [ { <expression1> }, { <expression2> } , ... , { <expressionN> } ] }
$not
字段值不匹配表达式或者字段值不存在
{ field: { $not: { <operator-expression> } } }
$nor
字段值不匹配所有的表达式的文档，包括那些不包含这些字段的文档
{ $nor: [ { <expression1> }, { <expression2> }, ... { <expressionN> } ] }
1.3元素操作符
$exists
<boolean> 等于true时，字段存在，包括字段值为null的文档
<boolean> 等于false时，字段不存在
{ field: { $exists: <boolean> } }
$type
匹配字段值为指定数据类型的文档
{ field: { $type: <BSON type number> | <String alias> } }
Type Number Alias Notes
Double 1 “double”
String 2 “string”
Object 3 “object”
Array 4 “array”
Binary data 5 “binData”
Undefined 6 “undefined” Deprecated.
ObjectId 7 “objectId”
Boolean 8 “bool”
Date 9 “date”
Null 10 “null”
Regular Expression 11 “regex”
DBPointer 12 “dbPointer” Deprecated.
JavaScript 13 “javascript”
Symbol 14 “symbol” Deprecated.
JavaScript (with scope) 15 “javascriptWithScope”
32-bit integer 16 “int”
Timestamp 17 “timestamp”
64-bit integer 18 “long”
Decimal128 19 “decimal” New in version 3.4.
Min key -1 “minKey”
Max key 127 “maxKey”
举例如下：
db.addressBook.insertMany(
[
{ "_id" : 1, address : "2030 Martian Way", zipCode : "90698345" },
{ "_id" : 2, address: "156 Lunar Place", zipCode : 43339374 },
{ "_id" : 3, address : "2324 Pluto Place", zipCode: NumberLong(3921412) },
{ "_id" : 4, address : "55 Saturn Ring" , zipCode : NumberInt(88602117) }
]
)
db.addressBook.find( { "zipCode" : { $type : 2 } } );
db.addressBook.find( { "zipCode" : { $type : "string" } } );
查询结果为：
{ "_id" : 1, "address" : "2030 Martian Way", "zipCode" : "90698345" }
1.4评估操作符
$mod
匹配字段值被除有指定的余数的文档
{ field: { $mod: [ divisor(除数), remainder(余数) ] } }
{ "_id" : 1, "item" : "abc123", "qty" : 0 }
{ "_id" : 2, "item" : "xyz123", "qty" : 5 }
{ "_id" : 3, "item" : "ijk123", "qty" : 12 }
db.inventory.find( { qty: { $mod: [ 4, 0 ] } } )
查询结果为：
{ "_id" : 1, "item" : "abc123", "qty" : 0 }
{ "_id" : 3, "item" : "ijk123", "qty" : 12 }
$regex
正则表达式可以匹配到的文档
{ <field>: { $regex: /pattern/, $options: '<options>' } }
{ <field>: { $regex: 'pattern', $options: '<options>' } }
{ <field>: { $regex: /pattern/<options> } }
Option Description Syntax Restrictions
i 对大小写不敏感
m 多行匹配
x 忽略空格
s 使点号可以匹配换行符
$text
针对创建了全文索引的字段进行文本搜索
{
$text:
{
$search: <string>,
$language: <string>,
$caseSensitive: <boolean>,
$diacriticSensitive: <boolean>
}
}
$where
可以通过js表达式或js函数来查询文档
1.5数组操作符
$all
字段值是包含所有指定元素的数组的文档
{ <field>: { $all: [ <value1> , <value2> ... ] } }
举例如下：
{
_id: ObjectId("5234cc89687ea597eabee675"),
code: "xyz",
tags: [ "school", "book", "bag", "headphone", "appliance" ],
}
{
_id: ObjectId("5234cc8a687ea597eabee676"),
code: "abc",
tags: [ "appliance", "school", "book" ],
}
{
_id: ObjectId("5234ccb7687ea597eabee677"),
code: "efg",
tags: [ "school", "book" ],
}
{
_id: ObjectId("52350353b2eff1353b349de9"),
code: "ijk",
tags: [ "electronics", "school" ],
}
db.inventory.find( { tags: { $all: [ "appliance", "school", "book" ] } } )
查询结果：
{
_id: ObjectId("5234cc89687ea597eabee675"),
code: "xyz",
tags: [ "school", "book", "bag", "headphone", "appliance" ],
}
{
_id: ObjectId("5234cc8a687ea597eabee676"),
code: "abc",
tags: [ "appliance", "school", "book" ],
}
$elemMatch
数组字段至少一个元素满足所有指定查询条件的文档
{ <field>: { $elemMatch: { <query1>, <query2>, ... } } }
$size
匹配数组字段元素个数等于指定数量的文档
db.collection.find( { field: { $size: 2 } } );
1.6投影操作符
$ (projection)
限定查询结果中指定数组字段返回满足条件的第一个元素
举例如下：
文档集合
{ "_id" : 1, "semester" : 1, "grades" : [ 70, 87, 90 ] }
{ "_id" : 2, "semester" : 1, "grades" : [ 90, 88, 92 ] }
{ "_id" : 3, "semester" : 1, "grades" : [ 85, 100, 90 ] }
{ "_id" : 4, "semester" : 2, "grades" : [ 79, 85, 80 ] }
{ "_id" : 5, "semester" : 2, "grades" : [ 88, 88, 92 ] }
{ "_id" : 6, "semester" : 2, "grades" : [ 95, 90, 96 ] }
查询语句
db.students.find( { semester: 1, grades: { $gte: 85 } },
{ "grades.$": 1 } )
查询结果
{ "_id" : 1, "grades" : [ 87 ] }
{ "_id" : 2, "grades" : [ 90 ] }
{ "_id" : 3, "grades" : [ 85 ] }
$elemMatch (projection)
限定查询结果中指定数组字段返回满足条件的第一个元素
举例如下
文档集合：
{
_id: 1,
zipcode: "63109",
students: [
{ name: "john", school: 102, age: 10 },
{ name: "jess", school: 102, age: 11 },
{ name: "jeff", school: 108, age: 15 }
]
}
{
_id: 2,
zipcode: "63110",
students: [
{ name: "ajax", school: 100, age: 7 },
{ name: "achilles", school: 100, age: 8 },
]
}
{
_id: 3,
zipcode: "63109",
students: [
{ name: "ajax", school: 100, age: 7 },
{ name: "achilles", school: 100, age: 8 },
]
}
{
_id: 4,
zipcode: "63109",
students: [
{ name: "barney", school: 102, age: 7 },
{ name: "ruth", school: 102, age: 16 },
]
}
查询语句：
db.schools.find( { zipcode: "63109" },
{ students: { $elemMatch: { school: 102 } } } )
查询结果：
{ "_id" : 1, "students" : [ { "name" : "john", "school" : 102, "age" : 10 } ] }
{ "_id" : 3 }
{ "_id" : 4, "students" : [ { "name" : "barney", "school" : 102, "age" : 7 } ] }
$slice (projection)
控制指定数组字段返回元素个数
db.collection.find( { field: value }, { array: {$slice: count } } );
2.更新操作符
2.1字段更新
$inc
给一个字段增加指定值
{ $inc: { <field1>: <amount1>, <field2>: <amount2>, ... } }
$mul
{ $mul: { field: <number> } }
$rename
{$rename: { <field1>: <newName1>, <field2>: <newName2>, ... } }
$setOnInsert
upsert为true时，有插入文档操作时插入指定字段值
db.collection.update(
<query>,
{ $setOnInsert: { <field1>: <value1>, ... } },
{ upsert: true }
)
$set
{ $set: { <field1>: <value1>, ... } }
$unset
删除指定字段
{ $unset: { <field1>: "", ... } }
$min
指定值小于当前值则更新为指定值
{ $min: { <field1>: <value1>, ... } }
$max
指定值大于当前值则更新为指定值
{ $max: { <field1>: <value1>, ... } }
$currentDate
设置字段值为当前日期
指定值为true设置为当前日期, 或者{ $type: “timestamp” }或{ $type: “date” }的形式”timestamp”和”date”必须是小写的
{ $currentDate: { <field1>: <typeSpecification1>, ... } }
2.2数组更新
$
更新指定数组的第一个元素
{ "<array>.$" : value }
$addToSet
数组字段增加一个值
{ $addToSet: { <field1>: <value1>, ... } }
$pop
删除数组字段中的第一个或最后一个元素
{ $pop: { <field>: <-1 | 1>, ... } }
$pullAll
删除数组字段中所有指定值，如果指定值为数组，则删除匹配数组内的元素
{ $pullAll: { <field1>: [ <value1>, <value2> ... ], ... } }
$pull
符合条件的值将被删除
{ $pull: { <field1>: <value|condition>, <field2>: <value|condition>, ... } }
$pushAll
向数组中追加多个指定值
{ $pushAll: { <field>: [ <value1>, <value2>, ... ] } }
$push
向数组中追加值
{ $push: { <field1>: <value1>, ... } }
$each
用于 $addToSet添加多个值到数组中
{ $addToSet: { <field>: { $each: [ <value1>, <value2> ... ] } } }
追加多个值到数组中
{ $push: { <field>: { $each: [ <value1>, <value2> ... ] } } }
$slice
限定$push操作时数组元素的个数
必须和$each一起使用
{
$push: {
<field>: {
$each: [ <value1>, <value2>, ... ],
$slice: <num>
}
}
}
$sort
与$each一起使用
{
$push: {
<field>: {
$each: [ <value1>, <value2>, ... ],
$sort: <sort specification>
}
}
}
$position
与$each一起使用
<num>从0开始的索引值
{
$push: {
<field>: {
$each: [ <value1>, <value2>, ... ],
$position: <num>
}
}
}
3.聚合管道操作符
$project
管道中字段的增加、删除和重命名
{ $project: { <specification(s)> } }
$match
{ $match: { <query> } }
$limit
{ $limit: <positive integer> }
$skip
{ $skip: <positive integer> }
$unwind
文档按照数组字段进行拆分
举例如下：
文档：
{ "_id" : 1, "item" : "ABC1", sizes: [ "S", "M", "L"] }
管道语句：
db.inventory.aggregate( [ { $unwind : "$sizes" } ] )
结果：
{ "_id" : 1, "item" : "ABC1", "sizes" : "S" }
{ "_id" : 1, "item" : "ABC1", "sizes" : "M" }
{ "_id" : 1, "item" : "ABC1", "sizes" : "L" }
$group
{ $group: { _id: <expression>, <field1>: { <accumulator1> : <expression1> }, ... } }
举例如下
文档集合：
{ "_id" : 8751, "title" : "The Banquet", "author" : "Dante", "copies" : 2 }
{ "_id" : 8752, "title" : "Divine Comedy", "author" : "Dante", "copies" : 1 }
{ "_id" : 8645, "title" : "Eclogues", "author" : "Dante", "copies" : 2 }
{ "_id" : 7000, "title" : "The Odyssey", "author" : "Homer", "copies" : 10 }
{ "_id" : 7020, "title" : "Iliad", "author" : "Homer", "copies" : 10 }
分组：
db.books.aggregate(
[
{ $group : { _id : "$author", books: { $push: "$title" } } }
]
)
结果：
{ "_id" : "Homer", "books" : [ "The Odyssey", "Iliad" ] }
{ "_id" : "Dante", "books" : [ "The Banquet", "Divine Comedy", "Eclogues" ] }
分组：
db.books.aggregate(
[
{ $group : { _id : "$author", books: { $push: "$$ROOT" } } }
]
)
结果：
{
"_id" : "Homer",
"books" :
[
{ "_id" : 7000, "title" : "The Odyssey", "author" : "Homer", "copies" : 10 },
{ "_id" : 7020, "title" : "Iliad", "author" : "Homer", "copies" : 10 }
]
}
{
"_id" : "Dante",
"books" :
[
{ "_id" : 8751, "title" : "The Banquet", "author" : "Dante", "copies" : 2 },
{ "_id" : 8752, "title" : "Divine Comedy", "author" : "Dante", "copies" : 1 },
{ "_id" : 8645, "title" : "Eclogues", "author" : "Dante", "copies" : 2 }
]
}
$sort
{ $sort: { <field1>: <sort order>, <field2>: <sort order> ... } }
$lookup
两个集合之间的关联
{
$lookup:
{
from: <collection to join>,
localField: <field from the input documents>,
foreignField: <field from the documents of the "from" collection>,
as: <output array field>
}
}
$count
{ $count: <string> }
