I am trying to query a table called "user_path_summary" for a value that is equal to my hashkey, "username" and also equal to my global secondary index hashkey, "full_path". I am hoping to get back one attribute, "articles_read". The parameters that I am using are:
var params = {
"TableName": "user_path_summary",
"IndexName": "full_path_index",
"KeyConditionExpression": "full_path = :v_full_path AND username = v:username",
"ExpressionAttributeValues": {
":v_username": {"S" : username},
":v_full_path": {"S": full_path}
},
"ProjectionExpression": "articles_read",
"ScanIndexForward": false
};
I get the following error.
{ [MultipleValidationErrors: There were 2 validation errors:
* MissingRequiredParameter: Missing required key 'KeyConditions' in params
* UnexpectedParameter: Unexpected key 'KeyConditionExpression' found in params]
message: 'There were 2 validation errors:\n* MissingRequiredParameter: Missing required key \'KeyConditions\' in params\n* UnexpectedParameter: Unexpected key \'KeyConditionExpression\' found in params',
code: 'MultipleValidationErrors',
errors:
[ { [MissingRequiredParameter: Missing required key 'KeyConditions' in params]
message: 'Missing required key \'KeyConditions\' in params',
code: 'MissingRequiredParameter',
time: Sat Aug 01 2015 14:54:52 GMT-0400 (EDT) },
{ [UnexpectedParameter: Unexpected key 'KeyConditionExpression' found in params]
message: 'Unexpected key \'KeyConditionExpression\' found in params',
code: 'UnexpectedParameter',
time: Sat Aug 01 2015 14:54:52 GMT-0400 (EDT) } ],
time: Sat Aug 01 2015 14:54:52 GMT-0400 (EDT) }
I am confused because the error pertains to the missing parameter "KeyConditions", which is identified as a legacy parameter in the query API Reference, and also to the unexpected parameter "KeyConditionExpression" which the api reference says to use instead of "KeyConditions".
Is there a setting somewhere that I am missing? Is my syntax messed up somewhere. Please let me know, I am clearly missing something.
Related
Objective
Refresh a partition using a query (override). Using these as a guide:
https://www.sqlbi.com/articles/using-process-add-in-tabular-models/
https://gist.github.com/dgosbell/a7bc9fe9ff5a99fdb4df5819b8760217#file-refresh-with-override-example-txt
Apparently the MS example is not correct: https://learn.microsoft.com/en-us/bi-reference/tmsl/refresh-command-tmsl#examples
TMSL Script
{
"refresh" : {
"type" : "add",
"objects" : [{
"database" : "dbname",
"table" : "tblname"
}
],
"overrides" : [{
"partitions" : [
{
"originalObject" : {
"database" : "dbname",
"table" : "tblname",
"partition" : "partname"
},
"source" : {
"query" :
"SELECT * FROM source.view WHERE date_field = '2014-12-06'"
}
}
]
}
]
}
}
Error Message
The JSON DDL request failed with the following error: Failed to execute XMLA. Error returned: 'The Process command for partition 'partname' in table 'tblname' cannot be executed because the pipeline rowset is missing.
'..
Technical Details:
RootActivityId: 89a6f9ac-e5d4-4eaa-b049-455190039b4b
Date (UTC): 6/28/2019 3:20:36 PM
0: PFError::SetLastError() line 2158 + 0x0 (sql\picasso\engine\src\pf\eh\pferror.cpp)
1: PFSetLastError() line 2906 + 0x0 (sql\picasso\engine\src\pf\eh\pferror.cpp)
2: ConvertExceptionsToPFResult<<lambda_764f81a97ea803a6bb1663c7971ce151> >() line 424 + 0x34 (sql\picasso\engine\src\pf\kernel\shared\pfshmacros.inl)
3: PFSetLastErrorExTag() line 3461 + 0x2e (sql\picasso\engine\src\pf\eh\pferror.cpp)
4: 0x00007FFAB599CC7E (symbolic name unavailable)
Other Info
Executed on SSMS directly and in Powershell (via Runbook) with same error message.
Question
What does this error message mean exactly? (It is very hard to find
helpful documentation.) Or, is there an alternative solution to refreshing
a partition using a query override?
You can only use either a Query or M partition sources
If you are using an M partition source the syntax is:
"source":{
"type":"m",
"expression":"…"
}
And if you are using a Query partition source the syntax is:
"source":{
"type":"query",
"query":"…",
"dataSource":"…"
}
I try to write a demo - deliverydemo base on bootcamp-cordapp and refer cordapp-example for my own Order Flow.
After Party A-C and Notary started by command "build/nodes/runnodes":
TokenIssueFlow is worked.
I can saw my Order Flow by "flow list" command in CLI.
But got "missing parameter name at index 0 {}" when try to start my order flow.
Thu Jul 26 09:41:51 CST 2018>>> flow start
OrderPlaceFlow$OrderPlaceRequestFlow buyer: PartyB, seller: PartyC,
sellingPrice: 12.9, downPayments: 0.1 flow start
OrderPlaceFlow$OrderPlaceRequestFlow buyer: PartyB, seller: PartyC,
sellingPrice: 12.9, downPayments: 0.1: exception: Could not parse as a
command: Method lambda$call$6 missing parameter name at index 0 Thu
Jul 26 09:41:55 CST 2018>>> E 09:41:55+0800 [pool-8-thread-8]
command.CRaSHSession.execute - Error while evaluating request 'flow
start OrderPlaceFlow$OrderPlaceRequestFlow buyer: PartyB, seller:
PartyC, sellingPrice: 12.9, downPayments: 0.1' flow start
OrderPlaceFlow$OrderPlaceRequestFlow buyer: PartyB, seller: PartyC,
sellingPrice: 12.9, downPayments: 0.1: exception: Could not parse as a
command: Method lambda$call$6 missing parameter name at index 0 {}
net.corda.client.jackson.StringToMethodCallParser$UnparseableCallException$ReflectionDataMissing:
Could not parse as a command: Method lambda$call$6 missing parameter
name at index 0 at
net.corda.client.jackson.StringToMethodCallParser.paramNamesFromMethod(StringToMethodCallParser.kt:131)
~[corda-jackson-corda-3.0.jar:?]
Thu Jul 26 09:38:32 CST 2018>>> flow list
com.cienet.deliverydemo.order.OrderPlaceFlow$OrderPlaceRequestFlow
com.cienet.deliverydemo.token.TokenIssueFlow
net.corda.core.flows.ContractUpgradeFlow$Authorise
net.corda.core.flows.ContractUpgradeFlow$Deauthorise
net.corda.core.flows.ContractUpgradeFlow$Initiate
Thu Jul 26 09:38:34 CST 2018>>>
public OrderPlaceRequestFlow(Party buyer, Party seller, float sellingPrice, float downPayments) {
this.buyer = buyer;
this.seller = seller;
this.sellingPrice = sellingPrice;
this.downPayments = downPayments;
}
I still do not know why, but that is working after build clean and re-build by:
./gradlew clean
./gradlew test
./gradlew deployNodesJava -Poffline=true
Sometimes, that is a re-build issue.
But, if you are using JAVA for a flow, and using session send/receive/unwarp, this error will rise. And not happen in Kotlin code.
EDIT:
I add a Kotlin code just for sending/receiving StateAndRef.
class TokenAsk(private val otherPartyFlow: FlowSession) {
#Suspendable
fun askTokenState(amount: Int, owner: Party): StateAndRef<TokenState> {
otherPartyFlow.send(amount)
otherPartyFlow.send(owner)
return otherPartyFlow.receive<StateAndRef<TokenState>>().unwrap { it }
}
#Suspendable
fun receiveAmount(): Int =
otherPartyFlow.receive<Int>().unwrap{it}
#Suspendable
fun receiveOwner(): Party =
otherPartyFlow.receive<Party>().unwrap{it}
#Suspendable
fun sendStateAndRef(tokenStateAndRef: StateAndRef<TokenState>) =
otherPartyFlow.send(tokenStateAndRef)
}
** EDIT 2 **
I faced this error again, when I am using Kotlin code.
I have to remove the "private" key word in the constructor of a Flow for avoiding this error.
From:
class Initiator(private val number: String, private val otherParty: Party) : FlowLogic<SignedTransaction>()
To:
class Initiator(val number: String, val otherParty: Party) : FlowLogic<SignedTransaction>()
I am using following code (MongoDB C# driver) to projects fields ,
where queryDocument = '{{ "FullName" : /myname/i }}'
BsonDocument projectionDefination = Builders.Projection.ToBsonDocument();
projectionDefination.Add(new BsonElement("FullName", "myname"));
collection.Find(queryDocument).Project(projectionDefination);
getting following error:
{"Command failed."}
{{ "_t" : "OKMongoResponse", "ok" : 0, "code" : 9, "errmsg" : "Syntax error, incorrect syntax near '9'.", "$err" : "Syntax error, incorrect syntax near '9'." }}
Can anyone update on this?
I also tried above with RoboMongo
Command: db.getCollection('Employee').find({ "FullName": /User/i}).projection({ "FullName" : "$FullName" })
Received following error:
Error: error: {
"_t" : "OKMongoResponse",
"ok" : 0,
"code" : 9,
"errmsg" : "Syntax error, incorrect syntax near '15'.",
"$err" : "Syntax error, incorrect syntax near '15'."
}
According to your description, I checked this issue and I could encounter the same issue:
As mongoDB document states about Projection in db.collection.find():
The projection parameter determines which fields are returned in the matching documents. The projection parameter takes a document of the following form:
{ field1: <value>, field2: <value> ... }
The <value> can be any of the following:
1 or true to include the field in the return documents.
0 or false to exclude the field.
Appreciate any help that you can provide.
I'm trying to create a 'Runway' model then attach 'Model' IDs for a many-to-many relationship within a transaction.
The model is still created when an error is thrown during attach (i.e. the transaction is not rolled back). What am I doing wrong?
export function create(object) {
var data = _.pick(object, ['name', 'userId']);
return Bookshelf.transaction((t) => {
return Runway.forge(data)
.save(null, {transaction: t})
.then((runway) => {
return runway.models().attach(object.models, {transaction: t});
})
})
.catch(err => {
winston.error('Error creating runway', {err: err});
throw err;
});
}
Logs:
Mon, 10 Oct 2016 06:07:59 GMT knex:tx trx1: Starting top level transaction
{ method: 'insert',
options: {},
timeout: false,
cancelOnTimeout: false,
bindings:
[ 2016-10-10T06:07:59.769Z,
'bf649bbf-c37f-426a-98e3-707e49eb17c6',
'my custom runway',
2016-10-10T06:07:59.769Z,
'66da84f6-45f4-4217-a995-dfb92cb246f1' ],
__knexQueryUid: 'c54606e4-7e4c-4a04-b66b-2f747df1ad6d',
sql: 'insert into `runways` (`created_at`, `id`, `name`, `updated_at`, `userId`) values (?, ?, ?, ?, ?)' }
{ method: 'insert',
options: {},
timeout: false,
cancelOnTimeout: false,
bindings:
[ 'f0a3bc21-2315-4b83-9cac-bab1fc019f1555',
'bf649bbf-c37f-426a-98e3-707e49eb17c6' ],
__knexQueryUid: '6125efce-3ef4-4327-a4ed-445634a26057',
sql: 'insert into `runways_models` (`modelId`, `runwayId`) values (?, ?)' }
Mon, 10 Oct 2016 06:07:59 GMT knex:tx trx1: releasing connection
2016-10-10T06:07:59.815Z ERROR [winston-fh] Error creating runway [METADATA]: {"err":{"message":"insert into `runways_models` (`modelId`, `runwayId`) values ('f0a3bc21-2315-4b83-9cac-bab1fc019f1555', 'bf649bbf-c37f-426a-98e3-707e49eb17c6') - ER_NO_REFERENCED_ROW_2: Cannot add or update a child row: a foreign key constraint fails (`figurehappy`.`runways_models`, CONSTRAINT `runways_models_modelid_foreign` FOREIGN KEY (`modelId`) REFERENCES `users` (`id`))","stack":"Error: ER_NO_REFERENCED_ROW_2: Cannot add or update a child row: a foreign key constraint fails (`figurehappy`.`runways_models`, CONSTRAINT `runways_models_modelid_foreign` FOREIGN KEY (`modelId`) REFERENCES `users` (`id`))\n at Query.Sequence._packetToError (/Users/Nim/Workspace/figurehappy/node_modules/mysql/lib/protocol/sequences/Sequence.js:51:14)\n at Query.ErrorPacket (/Users/Nim/Workspace/figurehappy/node_modules/mysql/lib/protocol/sequences/Query.js:83:18)\n at Protocol._parsePacket (/Users/Nim/Workspace/figurehappy/node_modules/mysql/lib/protocol/Protocol.js:280:23)\n at Parser.write (/Users/Nim/Workspace/figurehappy/node_modules/mysql/lib/protocol/Parser.js:74:12)\n at Protocol.write (/Users/Nim/Workspace/figurehappy/node_modules/mysql/lib/protocol/Protocol.js:39:16)\n at Socket.<anonymous> (/Users/Nim/Workspace/figurehappy/node_modules/mysql/lib/Connection.js:109:28)\n at emitOne (events.js:96:13)\n at Socket.emit (events.js:188:7)\n at readableAddChunk (_stream_readable.js:177:18)\n at Socket.Readable.push (_stream_readable.js:135:10)\n at TCP.onread (net.js:542:20)\n --------------------\n at Protocol._enqueue (/Users/Nim/Workspace/figurehappy/node_modules/mysql/lib/protocol/Protocol.js:141:48)\n at Connection.query (/Users/Nim/Workspace/figurehappy/node_modules/mysql/lib/Connection.js:214:25)\n at /Users/Nim/Workspace/figurehappy/node_modules/knex/lib/dialects/mysql/index.js:124:18\n at Promise._execute (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/debuggability.js:284:9)\n at Promise._resolveFromExecutor (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/promise.js:480:18)\n at new Promise (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/promise.js:77:14)\n at Client._query (/Users/Nim/Workspace/figurehappy/node_modules/knex/lib/dialects/mysql/index.js:118:12)\n at Client.query (/Users/Nim/Workspace/figurehappy/node_modules/knex/lib/client.js:187:24)\n at Runner.<anonymous> (/Users/Nim/Workspace/figurehappy/node_modules/knex/lib/runner.js:129:36)\n at Runner.tryCatcher (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/util.js:16:23)\n at Runner.query (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/method.js:15:34)\n at /Users/Nim/Workspace/figurehappy/node_modules/knex/lib/runner.js:55:21\n at tryCatcher (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/util.js:16:23)\n at /Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/using.js:185:26\n at tryCatcher (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/util.js:16:23)\n at Promise._settlePromiseFromHandler (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/promise.js:509:31)\n at Promise._settlePromise (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/promise.js:566:18)\n at Promise._settlePromise0 (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/promise.js:611:10)\n at Promise._settlePromises (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/promise.js:690:18)\n at Promise._fulfill (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/promise.js:635:18)\n at PromiseArray._resolve (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/promise_array.js:125:19)\n at PromiseArray._promiseFulfilled (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/promise_array.js:143:14)\n at Promise._settlePromise (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/promise.js:571:26)\n at Promise._settlePromise0 (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/promise.js:611:10)\n at Promise._settlePromises (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/promise.js:690:18)\n at Async._drainQueue (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/async.js:138:16)\n at Async._drainQueues (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/async.js:148:10)\n at Immediate.Async.drainQueues (/Users/Nim/Workspace/figurehappy/node_modules/bluebird/js/release/async.js:17:14)\n at runCallback (timers.js:570:20)\n at tryOnImmediate (timers.js:550:5)\n at processImmediate [as _immediateCallback] (timers.js:529:5)","code":"ER_NO_REFERENCED_ROW_2","errno":1452,"sqlState":"23000","index":0}}
insert into `runways_models` (`modelId`, `runwayId`) values ('f0a3bc21-2315-4b83-9cac-bab1fc019f1555', 'bf649bbf-c37f-426a-98e3-707e49eb17c6') - ER_NO_REFERENCED_ROW_2: Cannot add or update a child row: a foreign key constraint fails (`figurehappy`.`runways_models`, CONSTRAINT `runways_models_modelid_foreign` FOREIGN KEY (`modelId`) REFERENCES `users` (`id`))
Error: ER_NO_REFERENCED_ROW_2: Cannot add or update a child row: a foreign key constraint fails (`figurehappy`.`runways_models`, CONSTRAINT `runways_models_modelid_foreign` FOREIGN KEY (`modelId`) REFERENCES `users` (`id`))
Sorry... this was a User error.
I should have written {transacting: t} instead of {transaction: t}.
I have created Json response file in Company Home > Data Dictionary >
Web Scripts > org > alfresco > sample with the Name:
folder.get.json.ftl for one of the Alfresco Web
Script(http:// localhost:8080/alfresco/service/sample/folder/Company%20Home)according
to the guidelines mentioned in
http://docs.alfresco.com/4.0/index.jsp?topic=%2Fcom.alfresco.enterprise.doc%2Ftasks%2Fws-json-add.html.
After successful addition of the webscript , i have refresh the
Webscripts.
Now when im tring to call this websrcipt using the URL
http:// localhost:8080/alfresco/service/sample/folder/Company%20Home?format=json
i am getting Internal Error(500).
Please help me out regarding this.
Thanks in Advance!!!!
Below is the stack trace
{
"status" :
{
"code" : 500,
"name" : "Internal Error",
"description" : "An error inside the HTTP server which prevented it from fulfilling the request."
},
"message" : "01270141 Wrapped Exception (with status template): 01270216 Error during processing of the template 'Expression verbose is undefined on line 12, column 14 in org\/alfresco\/sample\/folder.get.json.ftl.'. Please contact your system administrator.",
"exception" : "org.springframework.extensions.webscripts.WebScriptException - 01270141 Wrapped Exception (with status template): 01270216 Error during processing of the template 'Expression verbose is undefined on line 12, column 14 in org\/alfresco\/sample\/folder.get.json.ftl.'. Please contact your system administrator.",
"callstack" :
[
"" ,"freemarker.core.InvalidReferenceException: Expression verbose is undefined on line 12, column 14 in org\/alfresco\/sample\/folder.get.json.ftl."
,"freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:125)"
,"freemarker.core.Expression.isTrue(Expression.java:145)"
,"freemarker.core.ConditionalBlock.accept(ConditionalBlock.java:77)"
,"freemarker.core.Environment.visit(Environment.java:221)"
,"freemarker.core.MixedContent.accept(MixedContent.java:92)"
,"freemarker.core.Environment.visit(Environment.java:221)"
,"freemarker.core.IteratorBlock$Context.runLoop(IteratorBlock.java:179)"
,"freemarker.core.Environment.visit(Environment.java:428)"
,"freemarker.core.IteratorBlock.accept(IteratorBlock.java:102)"
,"freemarker.core.Environment.visit(Environment.java:221)"
,"freemarker.core.MixedContent.accept(MixedContent.java:92)"
,"freemarker.core.Environment.visit(Environment.java:221)"
,"freemarker.core.Environment.process(Environment.java:199)"
,"org.alfresco.repo.template.FreeMarkerProcessor.process(FreeMarkerProcessor.java:202)"
,"org.springframework.extensions.webscripts.AbstractWebScript.renderTemplate(AbstractWebScript.java:714)"
,"org.springframework.extensions.webscripts.DeclarativeWebScript.renderFormatTemplate(DeclarativeWebScript.java:267)"
,"org.springframework.extensions.webscripts.DeclarativeWebScript.execute(DeclarativeWebScript.java:147)"
,"org.alfresco.repo.web.scripts.RepositoryContainer$2.execute(RepositoryContainer.java:400)"
,"org.alfresco.repo.transaction.RetryingTransactionHelper.doInTransaction(RetryingTransactionHelper.java:388)"
,"org.alfresco.repo.web.scripts.RepositoryContainer.transactionedExecute(RepositoryContainer.java:453)"
,"org.alfresco.repo.web.scripts.RepositoryContainer.transactionedExecuteAs(RepositoryContainer.java:491)"
,"org.alfresco.repo.web.scripts.RepositoryContainer.executeScript(RepositoryContainer.java:316)"
,"org.springframework.extensions.webscripts.AbstractRuntime.executeScript(AbstractRuntime.java:352)"
,"org.springframework.extensions.webscripts.AbstractRuntime.executeScript(AbstractRuntime.java:189)"
,"org.springframework.extensions.webscripts.servlet.WebScriptServlet.service(WebScriptServlet.java:118)"
,"javax.servlet.http.HttpServlet.service(HttpServlet.java:717)"
,"org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)"
,"org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)"
,"org.alfresco.web.app.servlet.GlobalLocalizationFilter.doFilter(GlobalLocalizationFilter.java:58)"
,"org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)"
,"org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)"
,"org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)"
,"org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)"
,"org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:465)"
,"org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)"
,"org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)"
,"org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)"
,"org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)"
,"org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:859)"
,"org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)"
,"org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1555)"
,"java.lang.Thread.run(Thread.java:619)"
,"org.alfresco.service.cmr.repository.TemplateException: 01270216 Error during processing of the template 'Expression verbose is undefined on line 12, column 14 in org\/alfresco\/sample\/folder.get.json.ftl.'. Please contact your system administrator."
,"org.alfresco.repo.template.FreeMarkerProcessor.process(FreeMarkerProcessor.java:206)"
,"org.springframework.extensions.webscripts.WebScriptException: 01270141 Wrapped Exception (with status template): 01270216 Error during processing of the template 'Expression verbose is undefined on line 12, column 14 in org\/alfresco\/sample\/folder.get.json.ftl.'. Please contact your system administrator."
,"org.springframework.extensions.webscripts.AbstractWebScript.createStatusException(AbstractWebScript.java:884)"
],
"server" : "Community v4.0.0 (a r30055) schema 5,016",
"time" : "Feb 27, 2012 9:53:23 AM"
}
The key line is:
freemarker.core.InvalidReferenceException: Expression verbose is undefined on line 12, column 14 in org/alfresco/sample/folder.get.json.ftl.
Your template, on line 12, character 14, you've referenced a variable "verbose" which doesn't exist. You should either set that variable in the model, or check if it's defined or not before using it.