背景简介

开发背景

• 开发环境：
  • docker中容器名：mongo（版本：mongo:4.2.3）
• mongo中相关配置：
  • 数据库（database）：audit
  • 表（或集合collection）：t_audit

条件操作符介绍

单个

操作符	说明	示例	类似于sql
$gt	大于	{"_id" : {$gt : 3 }}	where _id > 3
$lt	小于	{"_id" : {$lt : 3 }}	where _id < 3
$lte	不大于	{"_id" : {$lte : 3 }}	where _id <= 3
$gte	不小于	{"_id" : {$lte : 3 }}	where _id >= 3

组合

操作符	说明	示例	类似于sql
$gt 和 $lt	数字区间段	{"_id" : {$gt : 3, $lt: 10}}	where _id > 3 and _id < 10

时间操作

Date()

类型为：字符串

//Wed Dec 19 2012 01:03:25 GMT-0500 (EST)
Date() method which returns the current date as a string.

new Date()

类型为：字符串ISODate

//ISODate("2012-12-19T06:01:17.171Z")
new Date() constructor which returns a Date object using the ISODate() wrapper.

ISODate()

类型为：字符串ISODate

ISODate() constructor which returns a Date object using the ISODate() wrapper.

mongoexport 简介

官方解释：Export data from MongoDB in CSV or JSON format.
以json或csv格式导出数据

Usage:
  mongoexport <options>

Export data from MongoDB in CSV or JSON format.

mongoexport命令 参数比较多（不懂的时候，在shell中键入 mongoexport --help即可）

verbosity options:
  -v, --verbose=<level>                           more detailed log output (include multiple times for more verbosity, e.g. -vvvvv, or specify a numeric value, e.g. --verbose=N)
      --quiet                                     hide all log output

connection options:
  -h, --host=<hostname>                           mongodb host to connect to (setname/host1,host2 for replica sets)
      --port=<port>                               server port (can also use --host hostname:port)

ssl options:
      --ssl                                       connect to a mongod or mongos that has ssl enabled
      --sslCAFile=<filename>                      the .pem file containing the root certificate chain from the certificate authority
      --sslPEMKeyFile=<filename>                  the .pem file containing the certificate and key
      --sslPEMKeyPassword=<password>              the password to decrypt the sslPEMKeyFile, if necessary
      --sslCRLFile=<filename>                     the .pem file containing the certificate revocation list
      --sslAllowInvalidCertificates               bypass the validation for server certificates
      --sslAllowInvalidHostnames                  bypass the validation for server name
      --sslFIPSMode                               use FIPS mode of the installed openssl library

authentication options:
  -u, --username=<username>                       username for authentication
  -p, --password=<password>                       password for authentication
      --authenticationDatabase=<database-name>    database that holds the user's credentials
      --authenticationMechanism=<mechanism>       authentication mechanism to use

kerberos options:
      --gssapiServiceName=<service-name>          service name to use when authenticating using GSSAPI/Kerberos (default: mongodb)
      --gssapiHostName=<host-name>                hostname to use when authenticating using GSSAPI/Kerberos (default: <remote server's address>)

namespace options:
  -d, --db=<database-name>                        database to use
  -c, --collection=<collection-name>              collection to use

uri options:
      --uri=mongodb-uri                           mongodb uri connection string

output options:
  -f, --fields=<field>[,<field>]*                 comma separated list of field names (required for exporting CSV) e.g. -f "name,age"
      --fieldFile=<filename>                      file with field names - 1 per line
      --type=<type>                               the output format, either json or csv (defaults to 'json') (default: json)
  -o, --out=<filename>                            output file; if not specified, stdout is used
      --jsonArray                                 output to a JSON array rather than one object per line
      --pretty                                    output JSON formatted to be human-readable
      --noHeaderLine                              export CSV data without a list of field names at the first line
      --jsonFormat=<type>                         the extended JSON format to output, either canonical or relaxed (defaults to 'relaxed') (default: relaxed)

querying options:
  -q, --query=<json>                              query filter, as a JSON string, e.g., '{x:{$gt:1}}'
      --queryFile=<filename>                      path to a file containing a query filter (JSON)
  -k, --slaveOk                                   allow secondary reads if available (default true) (default: false)
      --readPreference=<string>|<json>            specify either a preference mode (e.g. 'nearest') or a preference json object (e.g. '{mode: "nearest", tagSets: [{a: "b"}], maxStalenessSeconds:
                                                  123}')
      --forceTableScan                            force a table scan (do not use $snapshot or hint _id). Deprecated since this is default behavior on WiredTiger
      --skip=<count>                              number of documents to skip
      --limit=<count>                             limit the number of documents to export
      --sort=<json>                               sort order, as a JSON string, e.g. '{x:1}'
      --assertExists                              if specified, export fails if the collection does not exist (default: false)

按时间段导出

需求：将数据库audit，集合t_audit中2020-12-10T16:00:00.000Z ~ 2020-12-10T16:59:59.999Z

mongoexport 在容器内生成csv

mongoexport -h localhost -u root -p 123456 --authenticationDatabase=admin --authenticationMechanism=SCRAM-SHA-1 --port 27017 -d audit -c t_audit --type=csv  -q '{"createTime": {"$gte": {"$date" : "2020-12-09T16:00:00.000Z"}}}' -f _id,userId,userName,accessIp,accessUrl,description,createTime,pushTime  -o /root/audit20201210_1.csv

虽然上一节中有mongoexport的参数说明，但还是再重复一下~

• -h 主机
• -u 用户
• -p 密码
• --authenticationDatabase 保存用户凭据的数据库
• --authenticationMechanism 使用的身份验证机制
• –port mongo服务端口号
• -d 数据库名
• -c 集合（表）名
• –type 导出格式
• -q 查询条件
• -f 查询字段（用逗号隔开）
• -o 导出文件名（容器内绝对路径）

docker cp将容器内csv复制到主机上

将容器中csv文件复制到主机/root/db/data目录里

docker cp mongo:/mongo/export.csv /root/db/data/

遇到的问题

query无法识别 $gt

出现问题：Failed: error parsing query as Extended JSON: invalid JSON input. Position: 20. Character: $

问题点：-q后面接收的参数非json格式，需要检查参数

–query=<json> query filter, as a JSON string, e.g., ‘{x:{$gt:1}}’
–queryFile=<filename>

解决方案：$gte 加上双引号

-q ‘{"_id": {$gte: 100}}’ -->> 改成 -q ‘{"_id": {"$gte": 100}}’

query无法识别 ISODate

出现问题：Failed: error parsing query as Extended JSON: invalid JSON input. Position: 20. Character: I

问题点：query参数无法识别ISODate

解决方案：$date
（在query条件中尝试过ISODate的各路写法，但是一直都会抛非法json格式，最后在万能的stackoverflow上找到了 $date，然后就愉快的解决了问题！）

 -q '{"createTime": {"$gte": {"$date" : "2020-12-09T16:00:00.000Z"}}}'

初次接触mongo，对它知之甚少，相关需求一来就懵圈，看来还是要不断摸索学习啊~~