mongo_shell()
Description:
Query
the databsase and return the query result.
Syntax:
mongo_shell(fd,s)
Note:
The function executes aMongoDB shell command s and returns the result. So far functions supported by s are find, count, distinct and aggregate.
Options:
|
@x |
Close the MongoDB connection automatically closes when the execution finishes; if the returned result is a cursor, disconnect from the database as the cursor closes. |
Parameters:
|
fd |
MongoDB connection object |
|
s |
An MongoDB function, which supports find, count, distinct and aggregate and follows the MongoDB syntax |
Return value:
A sequence/table sequence/cursor
Example:
|
|
A |
|
|
1 |
=mongo_open("mongodb://localhost:27017/mydb") |
Conncet to database mydb on MongoDB server |
|
2 |
=mongo_shell(A1,"emp.find()").fetch() |
Query records of the emp set in database mydb
|
|
3 |
=mongo_shell(A1,"emp.find({GENDER:\"F\"})") |
Query records where GENDER is F and return result as a cursor |
|
4 |
=A3.fetch() |
|
|
5 |
=mongo_shell@x(A1,"emp.count()") |
Use @x option to query the number of records, and close the connection after result is returned
|
|
6 |
=mongo_open("mongodb://localhost:27017/mydb") |
Connect to the MongoDB database |
|
7 |
=mongo_shell(A6,"emp.aggregate([{$group : {_id : \"$GENDER\", number : {$sum : 1}}}])") |
Count records by gender
|
|
8 |
=mongo_shell(A6,"emp.distinct(DEPT)") |
Query DEPT in the emp set to remove duplicate values
|
|
9 |
=mongo_close(A6) |
Close the database connection |
