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2021-12-13 21:45 |
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签到天数: 15 天 [LV.4]偶尔看看III
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查看全部数据表
>
use ChatRoom
switched to db ChatRoom
>
show collections
Account
Chat
system.indexes
system.users
创建数据表
>
db.createCollection(
"
Account
"
)
{
"
ok
"
:
1
}
>
db.createCollection(
"
Test
"
,{capped:true, size:
10000
}) {
"
ok
"
:
1
}
{
"
ok
"
:
1
}
-- 说明
capped:true，表示该集合的结构不能被修改；
size:在建表之初就指定一定的空间大小，接下来的插入操作会不断地按顺序APPEND数据在这个预分配好空间的文件中，如果已经超出空间大小，则回到文件头覆盖原来的数据继续插入。这种结构保证了插入和查询的高效性，它不允许删除单个记录，更新的也有限制：不能超过原有记录的大小。这种表效率很高，它适用于一些暂时保存数据的场合，比如网站中登录用户的session信息，又比如一些程序的监控日志，都是属于过了一定的时间就可以被覆盖的数据。
修改数据表名
>
db.Account.renameCollection(
"
Account1
"
)
{
"
ok
"
:
1
}
数据表帮助主题help
>
db.Account.help()
DBCollection help
db.Account.find().help()
-
show DBCursor help
db.Account.count()
db.Account.dataSize()
db.Account.distinct( key )
-
eg. db.Account.distinct(
"
x
"
)
db.Account.drop() drop the collection
db.Account.dropIndex(name)
db.Account.dropIndexes()
db.Account.ensureIndex(keypattern[,options])
-
options
is
an object with these possible fields: name, unique, dropDups
db.Account.reIndex()
db.Account.find([query],[fields])
-
query
is
an optional query filter. fields
is
optional set of fields to
return
.
e.g. db.Account.find( {x:
77
} , {name:
1
, x:
1
} )
db.Account.find(...).count()
db.Account.find(...).limit(n)
db.Account.find(...).skip(n)
db.Account.find(...).sort(...)
db.Account.findOne([query])
db.Account.findAndModify( { update : ... , remove : bool [, query: {}, sort: {},
"
new
"
: false] } )
db.Account.getDB() get DB object associated with collection
db.Account.getIndexes()
db.Account.group( { key : ..., initial: ..., reduce : ...[, cond: ...] } )
db.Account.mapReduce( mapFunction , reduceFunction ,
<
optional params
>
)
db.Account.remove(query)
db.Account.renameCollection( newName ,
<
dropTarget
>
) renames the collection.
db.Account.runCommand( name ,
<
options
>
) runs a db command with the given name where the first param
is
the collection name
db.Account.save(obj)
db.Account.stats()
db.Account.storageSize()
-
includes free space allocated to this collection
db.Account.totalIndexSize()
-
size
in
bytes of all the indexes
db.Account.totalSize()
-
storage allocated
for
all data
and
indexes
db.Account.update(query, object[, upsert_bool, multi_bool])
db.Account.validate()
-
SLOW
db.Account.getShardVersion()
-
only
for
use with sharding
查看全部表记录
>
db.Account.find()
{
"
_id
"
: ObjectId(
"
4df08553188e444d001a763a
"
),
"
AccountID
"
:
1
,
"
UserName
"
:
"
libing
"
,
"
Password
"
:
"
1
"
,
"
Age
"
:
26
,
"
Email
"
:
"
libing@126.com
"
,
"
RegisterDate
"
:
"
2011-06-09 16:31:25
"
}
{
"
_id
"
: ObjectId(
"
4df08586188e444d001a763b
"
),
"
AccountID
"
:
2
,
"
UserName
"
:
"
lb
"
,
"
Password
"
:
"
1
"
,
"
Age
"
:
25
,
"
Email
"
:
"
libing@163.com
"
,
"
RegisterDate
"
:
"
2011-06-09 16:36:95
"
}
--SELECT * FROM Account
说明：
默认每页显示20条记录，当显示不下的情况下，可以用it迭代命令查询下一页数据。
可以通过DBQuery.shellBatchSize设置每页显示数据的大小。如：DBQuery.shellBatchSize = 5，这样每页就显示5条记录了。
>
db.Test.find()
{
"
_id
"
: ObjectId(
"
4df6d55407444568af61cfea
"
),
"
TestID
"
:
1
}
{
"
_id
"
: ObjectId(
"
4df6d55907444568af61cfeb
"
),
"
TestID
"
:
2
}
{
"
_id
"
: ObjectId(
"
4df6d55b07444568af61cfec
"
),
"
TestID
"
:
3
}
{
"
_id
"
: ObjectId(
"
4df6d55e07444568af61cfed
"
),
"
TestID
"
:
4
}
{
"
_id
"
: ObjectId(
"
4df6d56207444568af61cfee
"
),
"
TestID
"
:
5
}
{
"
_id
"
: ObjectId(
"
4df6d56507444568af61cfef
"
),
"
TestID
"
:
6
}
{
"
_id
"
: ObjectId(
"
4df6d56807444568af61cff0
"
),
"
TestID
"
:
7
}
{
"
_id
"
: ObjectId(
"
4df6d56b07444568af61cff1
"
),
"
TestID
"
:
8
}
{
"
_id
"
: ObjectId(
"
4df6d56e07444568af61cff2
"
),
"
TestID
"
:
9
}
{
"
_id
"
: ObjectId(
"
4df6d57a07444568af61cff3
"
),
"
TestID
"
:
10
}
{
"
_id
"
: ObjectId(
"
4df6d57d07444568af61cff4
"
),
"
TestID
"
:
11
}
{
"
_id
"
: ObjectId(
"
4df6d58007444568af61cff5
"
),
"
TestID
"
:
12
}
{
"
_id
"
: ObjectId(
"
4df6d58307444568af61cff6
"
),
"
TestID
"
:
13
}
{
"
_id
"
: ObjectId(
"
4df6d58e07444568af61cff7
"
),
"
TestID
"
:
14
}
{
"
_id
"
: ObjectId(
"
4df6d59207444568af61cff8
"
),
"
TestID
"
:
15
}
{
"
_id
"
: ObjectId(
"
4df6d59607444568af61cff9
"
),
"
TestID
"
:
16
}
{
"
_id
"
: ObjectId(
"
4df6d59c07444568af61cffa
"
),
"
TestID
"
:
17
}
{
"
_id
"
: ObjectId(
"
4df6d5a307444568af61cffb
"
),
"
TestID
"
:
18
}
{
"
_id
"
: ObjectId(
"
4df6d5a607444568af61cffc
"
),
"
TestID
"
:
19
}
>
DBQuery.shellBatchSize
20
>
DBQuery.shellBatchSize
=
5
5
>
db.Test.find()
{
"
_id
"
: ObjectId(
"
4df6d55407444568af61cfea
"
),
"
TestID
"
:
1
}
{
"
_id
"
: ObjectId(
"
4df6d55907444568af61cfeb
"
),
"
TestID
"
:
2
}
{
"
_id
"
: ObjectId(
"
4df6d55b07444568af61cfec
"
),
"
TestID
"
:
3
}
{
"
_id
"
: ObjectId(
"
4df6d55e07444568af61cfed
"
),
"
TestID
"
:
4
}
{
"
_id
"
: ObjectId(
"
4df6d56207444568af61cfee
"
),
"
TestID
"
:
5
}
has more
>
it
{
"
_id
"
: ObjectId(
"
4df6d56507444568af61cfef
"
),
"
TestID
"
:
6
}
{
"
_id
"
: ObjectId(
"
4df6d56807444568af61cff0
"
),
"
TestID
"
:
7
}
{
"
_id
"
: ObjectId(
"
4df6d56b07444568af61cff1
"
),
"
TestID
"
:
8
}
{
"
_id
"
: ObjectId(
"
4df6d56e07444568af61cff2
"
),
"
TestID
"
:
9
}
{
"
_id
"
: ObjectId(
"
4df6d57a07444568af61cff3
"
),
"
TestID
"
:
10
}
has more
>
it
{
"
_id
"
: ObjectId(
"
4df6d57d07444568af61cff4
"
),
"
TestID
"
:
11
}
{
"
_id
"
: ObjectId(
"
4df6d58007444568af61cff5
"
),
"
TestID
"
:
12
}
{
"
_id
"
: ObjectId(
"
4df6d58307444568af61cff6
"
),
"
TestID
"
:
13
}
{
"
_id
"
: ObjectId(
"
4df6d58e07444568af61cff7
"
),
"
TestID
"
:
14
}
{
"
_id
"
: ObjectId(
"
4df6d59207444568af61cff8
"
),
"
TestID
"
:
15
}
has more
>
it
{
"
_id
"
: ObjectId(
"
4df6d59607444568af61cff9
"
),
"
TestID
"
:
16
}
{
"
_id
"
: ObjectId(
"
4df6d59c07444568af61cffa
"
),
"
TestID
"
:
17
}
{
"
_id
"
: ObjectId(
"
4df6d5a307444568af61cffb
"
),
"
TestID
"
:
18
}
{
"
_id
"
: ObjectId(
"
4df6d5a607444568af61cffc
"
),
"
TestID
"
:
19
}
>
it
no cursor
查询一条记录
>
db.Account.findOne()
{
"
_id
"
: ObjectId(
"
4ded95c3b7780a774a099b7c
"
),
"
UserName
"
:
"
libing
"
,
"
Password
"
:
"
1
"
,
"
Email
"
:
"
libing@126.cn
"
,
"
RegisterDate
"
:
"
2011-06-07 11:06:25
"
}
--SELECT TOP 1 * FROM Account
查询聚集中字段的不同记录
>
db.Account.distinct(
"
UserName
"
)
--SELECT DISTINCT("UserName") FROM Account
查询聚集中UserName包含“keyword”关键字的记录
db.Account.find({
"
UserName
"
:
/
keyword
/
})
--SELECT * FROM Account WHERE UserName LIKE "%keyword%"
查询聚集中UserName以"keyword" 开头的记录
>
db.Account.find({
"
UserName
"
:
/^
keyword
/
})
--SELECT * FROM Account WHERE UserName LIKE "keyword%"
查询聚集中UserName以“keyword”结尾的记录
>
db.Account.find({
"
UserName
"
:
/
keyword$
/
})
--SELECT * FROM Account WHERE UserName LIKE "%keyword"
查询聚集中指定列
>
db.Account.find({},{
"
UserName
"
:
1
,
"
Email
"
:
1
}) --1:true
--SELECT UserName,Email FROM Account
查询聚集中排除指定列
>
db.Account.find({},{
"
UserName
"
:0}) --0:false
查询聚集中指定列，且Age > 20
>
db.Account.find({
"
Age
"
:{
"
$gt
"
:
20
}},{
"
UserName
"
:
1
,
"
Email
"
:
1
})
--SELECT UserName,Email FROM Account WHERE Age > 20
聚集中字段排序
>
db.Account.find().sort({
"
UserName
"
:
1
})
--
升序
>
db.Account.find().sort({
"
UserName
"
:
-
1
})
--
降序
--SELECT * FROM Account ORDER BY UserName ASC
--SELECT * FROM Account ORDER BY UserName DESC
统计聚集中记录条数
>
db.Account.find().count()
--SELECT COUNT(*) FROM Account
统计聚集中符合条件的记录条数
>
db.Account.find({
"
Age
"
:{
"
$gt
"
:
20
}}).count()
-- SELECT COUNT(*) FROM Account WHERE Age > 20
统计聚集中字段符合条件的记录条数
>
db.Account.find({
"
UserName
"
:{
"
$exists
"
:true}}).count()
--SELECT COUNT(UserName) FROM Account
查询聚集中前5条记录
>
db.Account.find().limit(
5
)
--SELECT TOP 5 * FROM Account
查询聚集中第10条以后的记录
>
db.Account.find().skip(
10
)
--SELECT * FROM Account WHERE AccountID NOT IN (SELECT TOP 10 AccountID FROM Account)
查询聚集中第10条记录以后的5条记录
>
db.Account.find().skip(
10
).limit(
5
)
--SELECT TOP 5 * FROM Account WHERE AccountID NOT IN (SELECT TOP 10 AccountID FROM Account)
or查询
>
db.Account.find({
"
$or
"
:[{
"
UserName
"
:
/
keyword
/
},{
"
Email
"
:
/
keyword
/
}]},{
"
UserName
"
:true,
"
Email
"
:true})
--SELECT UserName,Email FROM Account WHERE UserName LIKE "%keyword%" OR Email LIKE "%keyword%"
添加新记录
>
db.Account.insert({AccountID:
2
,UserName:
"
lb
"
,Password:
"
1
"
,Age:
25
,Email:
"
libing@163.com
"
,RegisterDate:
"
2011-06-09 16:36:95
"
})
修改记录
>
db.Account.update({
"
AccountID
"
:
1
},{
"
$set
"
:{
"
Age
"
:
27
,
"
Email
"
:
"
libingql@163.com
"
}})
>
db.Account.find({
"
AccountID
"
:
1
})
{
"
AccountID
"
:
1
,
"
Age
"
:
27
,
"
Email
"
:
"
libingql@163.com
"
,
"
Password
"
:
"
1
"
,
"
RegisterDate
"
:
"
2011-06-09 16:31:25
"
,
"
UserName
"
:
"
libing
"
,
"
_id
"
: ObjectId(
"
4df08553188e444d001a763a
"
) }
>
db.Account.update({
"
AccountID
"
:
1
},{
"
$inc
"
:{
"
Age
"
:
1
}})
>
db.Account.find({
"
AccountID
"
:
1
})
{
"
AccountID
"
:
1
,
"
Age
"
:
28
,
"
Email
"
:
"
libingql@163.com
"
,
"
Password
"
:
"
1
"
,
"
RegisterDate
"
:
"
2011-06-09 16:31:25
"
,
"
UserName
"
:
"
libing
"
,
"
_id
"
: ObjectId(
"
4df08553188e444d001a763a
"
) }
删除记录
>
db.Account.remove({
"
AccountID
"
:
1
})
--
DELETE FROM Account WHERE AccountID
=
1
>
db.Account.remove({
"
UserName
"
:
"
libing
"
})
--
DELETE FROM Account WHERE UserName
=
"
libing
"
>
db.Account.remove({
"
Age
"
:{$lt:
20
}})
--
DELETE FROM Account WHERE Age
<
20
>
db.Account.remove({
"
Age
"
:{$lte:
20
}})
--
DELETE FROM Account WHERE Age
<=
20
>
db.Account.remove({
"
Age
"
:{$gt:
20
}})
--
DELETE FROM Account WHERE Age
>
20
>
db.Account.remove({
"
Age
"
:{$gte:
20
}})
--
DELETE FROM Account WHERE Age
>=
20
>
db.Account.remove({
"
Age
"
:{$ne:
20
}})
--
DELETE FROM Account WHERE Age
!=
20
>
db.Account.remove()
--
全部删除
>
db.Account.remove({})
--
全部删除
|
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发表于 2018-5-27 16:37:13