Powershell querying MongoDB - mongodb

Question

1) Here's my schema:
{
"_id" : ObjectId("53f4db1d968166157c2d57ce"),
"init" : "SJ",
"name" : "Steve Jobs",
"companies" : [
{
"_id" : ObjectId("53f4db1d968166157c2d57cf"),
"ticker" : "AAPL",
"compname" : "Apple"
},
{
"_id" : ObjectId("53f4db1d968166157c2d57d0"),
"ticker" : "MSFT",
"compname" : "Microsoft"
},
{
"_id" : ObjectId("53f4db1d968166157c2d57d1"),
"ticker" : "ABC",
"compname" : "iTunes"
},
{
"_id" : ObjectId("53f4db1d968166157c2d57d2"),
"ticker" : "DEF",
"compname" : "iPad Mini"
}
]
}
I'm trying to get a list of compnames, using Powershell & MongoDB. Here's what I have so far:
$databaseName = "CompanyInfo"
$collectionName = "comps"
$client = New-Object -TypeName MongoDB.Driver.MongoClient -ArgumentList "mongodb://localhost:27017"
$server = $client.GetServer()
$database = $server.GetDatabase($databaseName)
$collection = $database.GetCollection($collectionName)
$query['init'] = "SJ"
$results = $collection.FindOne($query)
foreach ($result in $results) {
write-host $result["companies.ticker"] /// Doesn't show me any records
}
This doesn't show me any records. How can I display companies.ticker info where init = "SJ"?
2) Btw, I get the following error after
$query['init'] = "SJ"
error
Cannot index into a null array.
At line:9 char:1
+ $query['init'] = "SJ"
+ ~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : NullArray
Any ideas as to why? I only have the MongoDB's standard index, which is on "_id", nothing else. My powershell script still works but I'm curious as to why I get that error.
[UPDATE Part 2] Thanks to #arco444, I no longer get error in part 2. Here's my revised code:
$query = #{'init' = "SJ"}
$collection.FindOne([MongoDB.Driver.QueryDocument]$query)
But I actually need help with part 1 - which is to display only the company tickers for a particular init. Any ideas on that one?
[ANSWER Part 1] Thanks again to #arco444 for directing me to the right path. After some tinkering around, I figured out what I missed. Here's my updated code:
$databaseName = "CompanyInfo"
$collectionName = "comps"
$client = New-Object -TypeName MongoDB.Driver.MongoClient -ArgumentList "mongodb://localhost:27017"
$server = $client.GetServer()
$database = $server.GetDatabase($databaseName)
$collection = $database.GetCollection($collectionName)
$query = new-object MongoDB.Driver.QueryDocument("init","SJ") /// Updated
$results = $collection.FindOne($query)
foreach ($result in $results["companies"]) { /// Updated
write-host $result["ticker"] /// Updated
}

Answer 1

From reading the MongoDB documentation, it looks like you need to initialise the query object properly first. Try this:
$query = new-object MongoDB.Driver.QueryDocument("init","SJ")
$results = $collection.FindOne($query)

Answer 2

Here's my updated code:
$databaseName = "CompanyInfo"
$collectionName = "comps"
$client = New-Object -TypeName MongoDB.Driver.MongoClient -ArgumentList "mongodb://localhost:27017"
$server = $client.GetServer()
$database = $server.GetDatabase($databaseName)
$collection = $database.GetCollection($collectionName)
$query = new-object MongoDB.Driver.QueryDocument("init","SJ") /// Updated
$results = $collection.FindOne($query)
foreach ($result in $results["companies"]) { /// Updated
write-host $result["ticker"] /// Updated
}

Answer 3

So when I use your query procedure with
$mongoDbDriverPath = 'D:\mongo\driver\'
$mongoServer = 'myserver:27000'
Add-Type -Path "$($mongoDbDriverPath)MongoDB.Bson.dll"
Add-Type -Path "$($mongoDbDriverPath)MongoDB.Driver.dll"
$databaseName = 'Tickets'
$collectionName = 'MongoUserTicket'
$client = New-Object -TypeName MongoDB.Driver.MongoClient -ArgumentList "mongodb://$mongoServer"
$server = $client.GetServer()
$database = $server.GetDatabase($databaseName)
$collection = $database.GetCollection($collectionName)
$query = new-object Mongodb.driver.querydocument('Id','5')
$query2 = New-object Mongodb.driver.querydocument('Type','User')
$results = #()
foreach($item in $collection.Find($query))
{
$results += $item
}
I get unexpected results for the query:
When piping to Get member for results I get this:
TypeName: MongoDB.Bson.BsonElement
Name MemberType Definition
---- ---------- ----------
Clone Method MongoDB.Bson.BsonElement Clone()
CompareTo Method int CompareTo(MongoDB.Bson.BsonElement other), int IComparable[BsonElement].CompareTo(MongoDB.Bson.BsonElement other)
DeepClone Method MongoDB.Bson.BsonElement DeepClone()
Equals Method bool Equals(MongoDB.Bson.BsonElement rhs), bool Equals(System.Object obj), bool IEquatable[BsonElement].Equals(MongoDB.Bson.BsonElement other)
GetHashCode Method int GetHashCode()
GetType Method type GetType()
ToString Method string ToString()
Name Property string Name {get;}
Value Property MongoDB.Bson.BsonValue Value {get;set;}
When entering $results on the shell prompt I get the data I expect:
$results
Name Value
---- -----
Id 5
AccessToken
CreatedOn 2013-09-27T22:05:52.246Z
TokenExpiration 2013-09-27T22:20:52.246Z
RefreshTokenExpiration 2013-09-28T22:05:52.246Z
ProfileToken BsonNull
Type User
Id 5
AccessToken
CreatedOn 2013-09-27T23:42:28.492Z
TokenExpiration 2013-09-27T23:57:28.492Z
RefreshTokenExpiration 2013-09-28T22:06:04.071Z
ProfileToken BsonNull
Type User

Answer 4

here is what allowed me to get an object that i could operate on:
$results = #()
foreach($item in $collection.Find($query))
{
$props = #{}
$item | foreach { $props[ $_.name ] = $_.value }
$pso = [pscustomobject]$props
$results += $pso
}
full code:
$mongoDbDriverPath = 'D:\mongo\driver\'
$mongoServer = 'myserver:27000'
Add-Type -Path "$($mongoDbDriverPath)MongoDB.Bson.dll"
Add-Type -Path "$($mongoDbDriverPath)MongoDB.Driver.dll"
$databaseName = 'Tickets'
$collectionName = 'MongoUserTicket'
$client = New-Object -TypeName MongoDB.Driver.MongoClient -ArgumentList "mongodb://$mongoServer"
$server = $client.GetServer()
$database = $server.GetDatabase($databaseName)
$collection = $database.GetCollection($collectionName)
$query = new-object Mongodb.driver.querydocument('Id','5')
$query2 = New-object Mongodb.driver.querydocument('Type','User')
$results = #()
foreach($item in $collection.Find($query))
{
$props = #{}
$item | foreach { $props[ $_.name ] = $_.value }
$pso = [pscustomobject]$props
$results += $pso
}
$results