Mongodb数据导出工具mongoexport和导入工具mongoimport介绍

爱被打了一巴掌 2022-06-17 08:22 81阅读 0赞

**一、导出工具mongoexport**

Mongodb中的mongoexport工具可以把一个collection导出成JSON格式或CSV格式的文件。可以通过参数指定导出的数据项，也可以根据指定的条件导出数据。mongoexport具体用法如下所示：

Shell代码 ![收藏代码][icon_star.png]

1.  \[root@localhost mongodb\]\# ./bin/mongoexport --help 
2.  Export MongoDB data to CSV, TSV or JSON files. 
3.  
4.  options: 
5.   \--help produce help message 
6.   \-v \[ --verbose \] be more verbose (include multiple times for more 
7.   verbosity e.g. -vvvvv) 
8.   \--version print the program's version and exit 
9.   \-h \[ --host \] arg mongo host to connect to ( <set name>/s1,s2 for 
10.  sets) 
11.  \--port arg server port. Can also use --host hostname:port 
12.  \--ipv6 enable IPv6 support (disabled by default) 
13.  \-u \[ --username \] arg username 
14.  \-p \[ --password \] arg password 
15.  \--dbpath arg directly access mongod database files in the given 
16.  path, instead of connecting to a mongod server - 
17.  needs to lock the data directory, so cannot be used 
18.  if a mongod is currently accessing the same path 
19.  \--directoryperdb if dbpath specified, each db is in a separate 
20.  directory 
21.  \--journal enable journaling 
22.  \-d \[ --db \] arg database to use 
23.  \-c \[ --collection \] arg collection to use (some commands) 
24.  \-f \[ --fields \] arg comma separated list of field names e.g. -f 
25.  name,age 
26.  \--fieldFile arg file with fields names - 1 per line 
27.  \-q \[ --query \] arg query filter, as a JSON string 
28.  \--csv export to csv instead of json 
29.  \-o \[ --out \] arg output file; if not specified, stdout is used 
30.  \--jsonArray output to a json array rather than one object per 
31.  line 
32.  \-k \[ --slaveOk \] arg (=1) use secondaries for export if available, default 
33.  true

参数说明：

\-h:指明数据库宿主机的IP

\-u:指明数据库的用户名

\-p:指明数据库的密码

\-d:指明数据库的名字

\-c:指明collection的名字

\-f:指明要导出那些列

\-o:指明到要导出的文件名

\-q:指明导出数据的过滤条件

实例：test库中存在着一个students集合，集合中数据如下：

Js代码 ![收藏代码][icon_star.png]

1.  > db.students.find() 
2.  \{ "\_id" : ObjectId("5031143350f2481577ea81e5"), "classid" : 1, "age" : 20, "name" : "kobe" \} 
3.  \{ "\_id" : ObjectId("5031144a50f2481577ea81e6"), "classid" : 1, "age" : 23, "name" : "nash" \} 
4.  \{ "\_id" : ObjectId("5031145a50f2481577ea81e7"), "classid" : 2, "age" : 18, "name" : "james" \} 
5.  \{ "\_id" : ObjectId("5031146a50f2481577ea81e8"), "classid" : 2, "age" : 19, "name" : "wade" \} 
6.  \{ "\_id" : ObjectId("5031147450f2481577ea81e9"), "classid" : 2, "age" : 19, "name" : "bosh" \} 
7.  \{ "\_id" : ObjectId("5031148650f2481577ea81ea"), "classid" : 2, "age" : 25, "name" : "allen" \} 
8.  \{ "\_id" : ObjectId("5031149b50f2481577ea81eb"), "classid" : 1, "age" : 19, "name" : "howard" \} 
9.  \{ "\_id" : ObjectId("503114a750f2481577ea81ec"), "classid" : 1, "age" : 22, "name" : "paul" \} 
10. \{ "\_id" : ObjectId("503114cd50f2481577ea81ed"), "classid" : 2, "age" : 24, "name" : "shane" \}

由上可以看出文档中存在着3个字段：classid、age、name

1.直接导出数据到文件中

Shell代码 ![收藏代码][icon_star.png]

1.  \[root@localhost mongodb\]\# ./bin/mongoexport -d test -c students -o students.dat 
2.  connected to: 127.0.0.1
3.  exported 9 records

命令执行完后使用ll命令查看，发现目录下生成了一个students.dat的文件

Shell代码 ![收藏代码][icon_star.png]

1.  \-rw-r--r-- 1 root root 869 Aug 21 00:05 students.dat

查看该文件信息，具体信息如下：

Shell代码 ![收藏代码][icon_star.png]

1.  \[root@localhost mongodb\]\# cat students.dat 
2.  \{ "\_id" : \{ "$oid" : "5031143350f2481577ea81e5" \}, "classid" : 1, "age" : 20, "name" : "kobe" \} 
3.  \{ "\_id" : \{ "$oid" : "5031144a50f2481577ea81e6" \}, "classid" : 1, "age" : 23, "name" : "nash" \} 
4.  \{ "\_id" : \{ "$oid" : "5031145a50f2481577ea81e7" \}, "classid" : 2, "age" : 18, "name" : "james" \} 
5.  \{ "\_id" : \{ "$oid" : "5031146a50f2481577ea81e8" \}, "classid" : 2, "age" : 19, "name" : "wade" \} 
6.  \{ "\_id" : \{ "$oid" : "5031147450f2481577ea81e9" \}, "classid" : 2, "age" : 19, "name" : "bosh" \} 
7.  \{ "\_id" : \{ "$oid" : "5031148650f2481577ea81ea" \}, "classid" : 2, "age" : 25, "name" : "allen" \} 
8.  \{ "\_id" : \{ "$oid" : "5031149b50f2481577ea81eb" \}, "classid" : 1, "age" : 19, "name" : "howard" \} 
9.  \{ "\_id" : \{ "$oid" : "503114a750f2481577ea81ec" \}, "classid" : 1, "age" : 22, "name" : "paul" \} 
10. \{ "\_id" : \{ "$oid" : "503114cd50f2481577ea81ed" \}, "classid" : 2, "age" : 24, "name" : "shane" \}

参数说明：

\-d:指明使用的库，本例中为test

\-c:指明要导出的集合，本例中为students

\-o:指明要导出的文件名，本例中为students.dat

从上面的结果可以看出，我们在导出数据时没有显示指定导出样式 ，默认导出了JSON格式的数据。如果我们需要导出CSV格式的数据，则需要使用--csv参数，具体如下所示：

Shell代码 ![收藏代码][icon_star.png]

1.  \[root@localhost mongodb\]\# ./bin/mongoexport -d test -c students --csv -f classid,name,age -o students\_csv.dat 
2.  connected to: 127.0.0.1
3.  exported 9 records 
4.  \[root@localhost mongodb\]\# cat students\_csv.dat 
5.  classid,name,age 
6.  1.0,"kobe",20.0
7.  1.0,"nash",23.0
8.  2.0,"james",18.0
9.  2.0,"wade",19.0
10. 2.0,"bosh",19.0
11. 2.0,"allen",25.0
12. 1.0,"howard",19.0
13. 1.0,"paul",22.0
14. 2.0,"shane",24.0
15. \[root@localhost mongodb\]\#

参数说明：

\-csv：指明要导出为csv格式

\-f：指明需要导出classid、name、age这3列的数据

由上面结果可以看出，mongoexport成功地将数据根据csv格式导出到了students\_csv.dat文件中。

**二、导入工具mongoimport**

Mongodb中的mongoimport工具可以把一个特定格式文件中的内容导入到指定的collection中。该工具可以导入JSON格式数据，也可以导入CSV格式数据。具体使用如下所示：

Shell代码 ![收藏代码][icon_star.png]

1.  \[root@localhost mongodb\]\# ./bin/mongoimport --help 
2.  options: 
3.   \--help produce help message 
4.   \-v \[ --verbose \] be more verbose (include multiple times for more 
5.   verbosity e.g. -vvvvv) 
6.   \--version print the program's version and exit 
7.   \-h \[ --host \] arg mongo host to connect to ( <set name>/s1,s2 for sets) 
8.   \--port arg server port. Can also use --host hostname:port 
9.   \--ipv6 enable IPv6 support (disabled by default) 
10.  \-u \[ --username \] arg username 
11.  \-p \[ --password \] arg password 
12.  \--dbpath arg directly access mongod database files in the given 
13.  path, instead of connecting to a mongod server - 
14.  needs to lock the data directory, so cannot be used 
15.  if a mongod is currently accessing the same path 
16.  \--directoryperdb if dbpath specified, each db is in a separate 
17.  directory 
18.  \--journal enable journaling 
19.  \-d \[ --db \] arg database to use 
20.  \-c \[ --collection \] arg collection to use (some commands) 
21.  \-f \[ --fields \] arg comma separated list of field names e.g. -f name,age 
22.  \--fieldFile arg file with fields names - 1 per line 
23.  \--ignoreBlanks if given, empty fields in csv and tsv will be ignored 
24.  \--type arg type of file to import. default: json (json,csv,tsv) 
25.  \--file arg file to import from; if not specified stdin is used 
26.  \--drop drop collection first 
27.  \--headerline CSV,TSV only - use first line as headers 
28.  \--upsert insert or update objects that already exist 
29.  \--upsertFields arg comma-separated fields for the query part of the 
30.  upsert. You should make sure this is indexed 
31.  \--stopOnError stop importing at first error rather than continuing 
32.  \--jsonArray load a json array, not one item per line. Currently 
33.  limited to 4MB.

参数说明：

\-h:指明数据库宿主机的IP

\-u:指明数据库的用户名

\-p:指明数据库的密码

\-d:指明数据库的名字

\-c:指明collection的名字

\-f:指明要导入那些列

示例：先删除students中的数据，并验证

Js代码 ![收藏代码][icon_star.png]

1.  > db.students.remove() 
2.  > db.students.find() 
3.  >

然后再导入上面导出的students.dat文件中的内容

Shell代码 ![收藏代码][icon_star.png]

1.  \[root@localhost mongodb\]\# ./bin/mongoimport -d test -c students students.dat 
2.  connected to: 127.0.0.1
3.  imported 9 objects 
4.  \[root@localhost mongodb\]\#

参数说明：

\-d:指明数据库名，本例中为test

\-c:指明collection名，本例中为students

students.dat：导入的文件名

查询students集合中的数据

Js代码 ![收藏代码][icon_star.png]

证明数据导入成功

上面演示的是导入JSON格式的文件中的内容，如果要导入CSV格式文件中的内容，则需要通过--type参数指定导入格式，具体如下所示：

先删除数据

Js代码 ![收藏代码][icon_star.png]

1.  > db.students.remove() 
2.  > db.students.find() 
3.  >

再导入之前导出的students\_csv.dat文件

Shell代码 ![收藏代码][icon_star.png]

1.  \[root@localhost mongodb\]\# ./bin/mongoimport -d test -c students --type csv --headerline --file students\_csv.dat 
2.  connected to: 127.0.0.1
3.  imported 10 objects 
4.  \[root@localhost mongodb\]\#

参数说明：

\-type:指明要导入的文件格式

\-headerline:指明第一行是列名，不需要导入

\-file：指明要导入的文件

查询students集合，验证导入是否成功：

Js代码 ![收藏代码][icon_star.png]

1.  > db.students.find() 
2.  \{ "\_id" : ObjectId("503266029355c632cd118ad8"), "classid" : 1, "name" : "kobe", "age" : 20 \} 
3.  \{ "\_id" : ObjectId("503266029355c632cd118ad9"), "classid" : 1, "name" : "nash", "age" : 23 \} 
4.  \{ "\_id" : ObjectId("503266029355c632cd118ada"), "classid" : 2, "name" : "james", "age" : 18 \} 
5.  \{ "\_id" : ObjectId("503266029355c632cd118adb"), "classid" : 2, "name" : "wade", "age" : 19 \} 
6.  \{ "\_id" : ObjectId("503266029355c632cd118adc"), "classid" : 2, "name" : "bosh", "age" : 19 \} 
7.  \{ "\_id" : ObjectId("503266029355c632cd118add"), "classid" : 2, "name" : "allen", "age" : 25 \} 
8.  \{ "\_id" : ObjectId("503266029355c632cd118ade"), "classid" : 1, "name" : "howard", "age" : 19 \} 
9.  \{ "\_id" : ObjectId("503266029355c632cd118adf"), "classid" : 1, "name" : "paul", "age" : 22 \} 
10. \{ "\_id" : ObjectId("503266029355c632cd118ae0"), "classid" : 2, "name" : "shane", "age" : 24 \} 
11. >

说明已经导入成功

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