question Can I use dynamic variable in NiFi expression language? in Archives of Support Questions (Read Only)

Can I use dynamic variable in NiFi expression language?

prachisharma432 — Wed, 30 May 2018 21:23:04 GMT

I am trying to write NiFi expression for routeonattribute processor as below:

${db.table.schema:toLower():in(${IncludeSchemaList}):and(${db.table.name:toLower():in(${ExcludeTableList}):not()})}

IncludeSchemaList and ExcludeTableList are provided in variables and added onto the flowfile as an attribute with updateattribute processor. The above In clause is treating the variables as literals and not working.

If I hard code the variables it looks like this:

${db.table.schema:toLower():in("dbo","hilton","archive","audit", "util"):and(${db.table.name:toLower():in("couponcodes","batch_job_execution_context","batch_step_execution"):not()})}

I hope someone knows how to solve for this. I would like to parameterize the schemanames to include and tables names to exclude in variables.

Thanks.

Re: Can I use dynamic variable in NiFi expression language?

falbani — Thu, 31 May 2018 01:03:36 GMT

@Prachi Sharma I think you should try something like this:

${anyDelineatedValue("${IncludeSchemaList}", ","):equals("${db.table.schema}"):and(anyDelineatedValue("${ExcludeTableList}", ","):equals("${db.table.schema}"):not())}

while having

IncludeSchemaList=dbo,hilton,archive,audit,util
ExcludeTableList=couponcodes,batch_job_execution_context,batch_step_execution

HTH

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Re: Can I use dynamic variable in NiFi expression language?

prachisharma432 — Thu, 31 May 2018 03:35:03 GMT

Thanks, I appreciate the quick response. I had to tweak the approach a bit, but this worked great!

I used two routeonattribute processor as the not() was posing issues.

First apply schema filter allows matches to flow through using below:

${anyDelineatedValue("${IncludeSchemaList}", ","):equalsIgnoreCase("${db.table.schema}")}

Then I apply table filter and only allow unmatched to flow through, using below:

${anyDelineatedValue("${ExcludeTableList}", ","):equalsIgnoreCase("${db.table.name}")}