It is a mongo terminal problem,
#!/bin/bash
echo
echo "Hello $USER."
echo "--------------------------"
mongo < myScript.js
with myScript.js as
if (hereAFunctionCheckExistsDatabase('myDatabase'))
doSomething()
exit
Of course show dbs work, but is a echo, I need a function.
My mongo:
MongoDB shell version: 2.4.10
connecting to: test
You need
function hereAFunctionCheckExistsDatabase(db) {
return (db.getMongo().getDBNames().indexOf(db)!=-1);
}
Mongo have also a catalog of namespaces, try this
db.system.namespaces.find( { name: /myDatabase\./ } );
...
Related
i am trying to pull records form mongo data base with json format to do that i am running below js :
conatin of get_DRMPhysicalresources_Data.js
cursor = db.physicalresources.find().limit(10)
while ( cursor.hasNext() ){
print( JSON.stringify(cursor.next()) );
}
the command i run to get the records :
mongo host_name:port/data_base_name -u user -p 'password' --eval "load(\"get_DRMPhysicalresources_Data.js\")" > DRMPhysicalresources.json
and i am able to get the result as josn formate inside DRMPhysicalresources.json , now i want to switch to other data base using use command i try add use db as below :
conatin of get_DRMPhysicalresources_Data.js
use db2_test
cursor = db.physicalresources.find().limit(10)
while ( cursor.hasNext() ){
print( JSON.stringify(cursor.next()) );
}
the command i run to get the records :
mongo host_name:port/data_base_name -u user -p 'password' --eval "load(\"get_DRMPhysicalresources_Data.js\")" > DRMPhysicalresources.json
but i am getting below errors :
MongoDB shell version v4.2.3
connecting to: "some data base info"
Implicit session: session { "id" : UUID("8c85c6af-ebed-416d-9ab8-d6739a4230cb") }
MongoDB server version: 4.4.11
WARNING: shell and server versions do not match
2022-04-11T13:39:30.121+0300 E QUERY [js] uncaught exception: SyntaxError: unexpected token: identifier :
#(shell eval):1:1
2022-04-11T13:39:30.122+0300 E QUERY [js] Error: error loading js file: get_DRMPhysicalresources_Data.js :
#(shell eval):1:1
2022-04-11T13:39:30.122+0300 E - [main] exiting with code -4
is there are any way to add use db2_test without break it ?
You can try this:
db = new Mongo().getDB("myOtherDatabase");
or
db = db.getSiblingDB('myOtherDatabase')
( this is the exact js equivalent to the 'use database' helper)
docs
when i try to run this command on cmd.
mongo test --eval 'db.testcollection.find({ createdate: {$gte: ISODate("2020-07-28 10:08:37.579Z"),$lt: ISODate("2020-08-04 13:42:40.975Z")}}, {place:1, _id:0}).forEach(function(x) { print(x.place); })'
it throws this error
MongoDB server version: 4.0.5
2020-08-06T13:33:49.336+0530 E QUERY [js] SyntaxError: missing ; before statement #(shell eval):1:19
i try to add a semicolon at the end. it still throws same error.
mongo test --eval 'db.testcollection.find({ createdate: {$gte: ISODate("2020-07-28 10:08:37.579Z"),$lt: ISODate("2020-08-04 13:42:40.975Z")}}, {place:1, _id:0}).forEach(function(x) { print(x.place); });'
Error is at line 1, column 19. So placing ; at the end will not solve the issue.
Could you use
mongo --eval 'db.testcollection.find({ createdate: {$gte: ISODate("2020-07-28 10:08:37.579Z"),$lt: ISODate("2020-08-04 13:42:40.975Z")}}, {place:1, _id:0}).forEach(function(x) { print(x.place); })' test
test is the db name where testcollection is present.
I've recently re-installed Mongodb switching from the enterprise to the community version. Nevertheless, when I start mongo, this is the prompt format I get:
MongoDB Enterprise >
How can I change it to the standard prompt version? (i.e., > if I am not wrong)
You can change the prompt from within a shell session by setting the prompt variable. For example, issuing the following command within a Mongo shell ...
var prompt="this_prompt >"
... will result in the shell's prompt changing to:
this_prompt >
You can change the default prompt for all future sessions by updating your .mongorc.js (you'll find this in your $HOME directory and if it does not exist then just create it). The following addition to your .mongorc.js ...
var prompt=function() {
return ISODate().toLocaleTimeString() + " > ";
}
... will result in this prompt:
:~/dev/tools/mongodb/mongodb-osx-x86_64-3.4.7/bin$ ./mongo
MongoDB shell version v3.4.7
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.4.7
16:09:43 >
16:09:57 >
Or, to get this prompt: > just add the following to your .mongorc.js:
var prompt=">"
There remains the sub text to your question, namely; where is the existing MongoDB Enterprise > prompt coming from?. It's hard to say but ...
Perhaps you have a Global mongorc.js; have a look in /etc/mongorc.js if you are on a *nix system or %ProgramData%\MongoDB if you are on Windows
Mongo behavour when finding a rc file is also subject to environment variables, more details in the docs.
When you search the internet for this topic then often you find the function below. If you like to include the existing prompt then use function defaultPrompt(), e.g.
prompt = function() {
if (typeof db == 'undefined')
return '(nodb)> ';
// Check the last db operation
try {
db.runCommand( {getLastError:1} );
} catch (e) {
print(e);
}
var user = db.runCommand({connectionStatus : 1}).authInfo.authenticatedUsers[0]
if (user) {
return user.user + "#" + db + " " + defaultPrompt();
} else {
return "(anonymous)#" + db + " " + defaultPrompt();
//return db + " " + defaultPrompt(); // if you prefer
}
}
Prompts will be like this:
admin#mip mongos>
mip shard001:ARBITER>
admin#mip configRepSet:PRIMARY>
Here is an example query:
db.readings.find( {"_id.s" : ISODate("2012-11-01T00:05:00Z") } ).count()
Query works in the mongo shell. However, in a bash script or directly in the Ubuntu shell
mongo fivemin --eval "printjson(db.readings.find( {"_id.s" : ISODate("2012-11-01T00:05:00Z") } ).count())"
returns a SyntaxError: missing : after property id (shell eval):1
I can't seem to find a problem with the query. I reverted to { "_id" : {"s" : ...} }, and it still gives the same problem. find().count() works however.
Had the same issue in bash shell.
This will fail because of double quotes:
mongo fivemin --eval "printjson(db.readings.find( {"_id.s" : ISODate("2012-11-01T00:05:00Z") } ).count())"
But using the eval string in single quote it works:
mongo fivemin --eval 'printjson(db.readings.find( {"_id.s" : ISODate("2012-11-01T00:05:00Z") } ).count())'
And if you use a $ sign like $regex you need to escape it:
mongo fivemin --eval 'printjson(db.readings.find( {"_id.s" : {"\$regex":"2012-11-01T*"} } ).count())'
use single quotes into double,
e.g.:
mongo fivemin --eval "printjson(db.readings.find( {'_id.s' : ISODate('2012-11-01T00:05:00Z') } ).count())"
There is also another possible issue using --eval with bash double quotes, if the query contains mongo operators i.e. $ne, $gt etc, since operators start with $.
double quotes:
$ echo " '$ne': null "
$ => '': null
single quotes:
$ echo ' "$ne": null '
$ => "$ne": null
Bash tries to replace these operators with variables.
$ ne = 'test'
$ echo " '$ne': null "
$ => 'test': null
So, I always recommend to use --eval with single quotes.
Just sat and thought about it. It seems to be a problem with bash exiting out on the " (should have noticed immediately!). Instead I used ' (or I guess you can use /" for JSON) so the query looks like:
printjson(db.readings.find({'_id.s' : ISODate('2013-01-01T00:05:00Z') }).count())"
The best way to handle this is to build the mongo command in a var. Then use eval command to execute the mongo command:
mongo_update_query="db.collectionName.update({ name:\""${some_name}"\", \
{ \$addToSet: { nick_names : { \$each : [ ${name_array} ] }}});"
mongo_cmd_str=$(echo "mongo --host ${mongo_host} --port ${mongo_port} ${mongo_database} --eval '${mongo_update_query}'")
# the actual call to mongo query
eval ${mongo_cmd_str}
I am trying to get variety working with db.eval() instead of commandline --eval. This is because I get some problems with authentication.
The normal use is from the commandline:
$ mongo test --eval "var collection = 'users', maxDepth = 3" /path/to/variety.js
What I am trying to do is this:
$ mongo
>> use admin
>> db.auth("foo", "bar")
>> use anotherColl
>> db.eval("/path/to/variety.js", "var collection = 'users', maxDepth = 3")
>> Thu Mar 7 13:19:10 uncaught exception: {
"errmsg" : "compile failed: JS Error: SyntaxError: invalid flag after regular expression nofile_a:0",
"ok" : 0
}
Is there a way to have db.eval() eat an javascript file instead of an string?
According to #Sammaye and my gut feeling you can't put in .js files in db.eval(). However for variety there is an solution described here.
mongo -u USER-p PASS admin --eval "var collection = 'COL', db_name='DB_NAME'" variety.js
And now the authentication problem :(