Azure ForEach activity failing with: The function 'length' expects its parameter to be an array or a string. The provided value is of type 'Integer' - azure

Question

How do I convert my value to an integer?
Here's added context if helpful:
My pipeline should get the column count of a blob CSV and pass that count to a ForEach activity. A switch activity is embedded in ForEach, but the pipeline is failing at ForEach with this error: 'The function 'length' expects its parameter to be an array or a string. The provided value is of type 'Integer'.
Metadata output:
{
"columnCount": 52,
"effectiveIntegrationRuntime": "AutoResolveIntegrationRuntime (Central US)",
"executionDuration": 1,
"durationInQueue": {
"integrationRuntimeQueue": 0
},
"billingReference": {
"activityType": "PipelineActivity",
"billableDuration": [
{
"meterType": "AzureIR",
"duration": 0.016666666666666666,
"unit": "Hours"
}
]
}
}
ForEach input:
{
"items": "#activity('Get Metadata1').output.columnCount",
"activities": [
{
"name": "Switch1",
"type": "Switch",
"dependsOn": [],
"userProperties": [],
"typeProperties": {
"on": "#item()",
"cases": [
{
"value": "44",
"activities": [
{
"name": "Copy data1_copy1",
"type": "Copy",
"dependsOn": [],
"policy": {
"timeout": "0.12:00:00",
"retry": 0,
"retryIntervalInSeconds": 30,
"secureOutput": false,
"secureInput": false
},
"userProperties": [],
"typeProperties": {
"source": {
"type": "DelimitedTextSource",
"storeSettings": {
"type": "AzureBlobStorageReadSettings",
"recursive": false,
"enablePartitionDiscovery": false
},
"formatSettings": {
"type": "DelimitedTextReadSettings"
}
},
"sink": {
"type": "AzureSqlSink",
"writeBehavior": "insert",
"sqlWriterUseTableLock": false
},
"enableStaging": false,
"translator": {
"type": "TabularTranslator",
"typeConversion": true,
"typeConversionSettings": {
"allowDataTruncation": true,
"treatBooleanAsNumber": false
}
}
},
"inputs": [
{
"referenceName": "ten_eighty_split_CSV",
"type": "DatasetReference",
"parameters": {
"FileName": "#pipeline().parameters.SourceFile"
}
}
],
"outputs": [
{
"referenceName": "ten_eighty_split_10_15_SQL",
"type": "DatasetReference",
"parameters": {}
}
]
}
]
},
{
"value": "52",
"activities": [
{
"name": "Copy data2_copy1",
"type": "Copy",
"dependsOn": [],
"policy": {
"timeout": "0.12:00:00",
"retry": 0,
"retryIntervalInSeconds": 30,
"secureOutput": false,
"secureInput": false
},
"userProperties": [],
"typeProperties": {
"source": {
"type": "DelimitedTextSource",
"storeSettings": {
"type": "AzureBlobStorageReadSettings",
"recursive": false,
"enablePartitionDiscovery": false
},
"formatSettings": {
"type": "DelimitedTextReadSettings"
}
},
"sink": {
"type": "AzureSqlSink",
"writeBehavior": "insert",
"sqlWriterUseTableLock": false
},
"enableStaging": false,
"translator": {
"type": "TabularTranslator",
"typeConversion": true,
"typeConversionSettings": {
"allowDataTruncation": true,
"treatBooleanAsNumber": false
}
}
},
"inputs": [
{
"referenceName": "ten_eighty_split_CSV",
"type": "DatasetReference",
"parameters": {
"FileName": "#pipeline().parameters.SourceFile"
}
}
],
"outputs": [
{
"referenceName": "ten_eighty_split_15_20_SQL",
"type": "DatasetReference",
"parameters": {}
}
]
}
]
},
{
"value": "60",
"activities": [
{
"name": "Copy data3_copy1",
"type": "Copy",
"dependsOn": [],
"policy": {
"timeout": "0.12:00:00",
"retry": 0,
"retryIntervalInSeconds": 30,
"secureOutput": false,
"secureInput": false
},
"userProperties": [],
"typeProperties": {
"source": {
"type": "DelimitedTextSource",
"storeSettings": {
"type": "AzureBlobStorageReadSettings",
"recursive": false,
"enablePartitionDiscovery": false
},
"formatSettings": {
"type": "DelimitedTextReadSettings"
}
},
"sink": {
"type": "AzureSqlSink",
"writeBehavior": "insert",
"sqlWriterUseTableLock": false
},
"enableStaging": false,
"translator": {
"type": "TabularTranslator",
"typeConversion": true,
"typeConversionSettings": {
"allowDataTruncation": true,
"treatBooleanAsNumber": false
}
}
},
"inputs": [
{
"referenceName": "ten_eighty_split_CSV",
"type": "DatasetReference",
"parameters": {
"FileName": "#pipeline().parameters.SourceFile"
}
}
],
"outputs": [
{
"referenceName": "ten_eighty_split_25_30_SQL",
"type": "DatasetReference",
"parameters": {}
}
]
}
]
},
{
"value": "68",
"activities": [
{
"name": "Copy data4_copy1",
"type": "Copy",
"dependsOn": [],
"policy": {
"timeout": "0.12:00:00",
"retry": 0,
"retryIntervalInSeconds": 30,
"secureOutput": false,
"secureInput": false
},
"userProperties": [],
"typeProperties": {
"source": {
"type": "DelimitedTextSource",
"storeSettings": {
"type": "AzureBlobStorageReadSettings",
"recursive": false,
"enablePartitionDiscovery": false
},
"formatSettings": {
"type": "DelimitedTextReadSettings"
}
},
"sink": {
"type": "AzureSqlSink",
"writeBehavior": "insert",
"sqlWriterUseTableLock": false
},
"enableStaging": false,
"translator": {
"type": "TabularTranslator",
"typeConversion": true,
"typeConversionSettings": {
"allowDataTruncation": true,
"treatBooleanAsNumber": false
}
}
},
"inputs": [
{
"referenceName": "ten_eighty_split_CSV",
"type": "DatasetReference",
"parameters": {
"FileName": "#pipeline().parameters.SourceFile"
}
}
],
"outputs": [
{
"referenceName": "ten_eighty_split_30_35_SQL",
"type": "DatasetReference",
"parameters": {}
}
]
}
]
}
]
}
}
]
}
ForEach output:
{}
Not sure how to satisfy this error. Thanks!

Answer 1

Failure type: User configuration issue
Details: The function 'length' expects its parameter to be an array or a string. The provided value is of type 'Integer'.
Since you use an integer value (columnCount) as an input to for-each activity, you are getting this error. If you have array of values and you want to iterate the activity based on each value of array, you can use for-each activity. In this case, you can use the switch case activity directly after get metadata activity. In Switch activity, expression is given within braces {...} .
Expression:
#{activity('Get Metadata1').output.columnCount}
I tried this in my environment and got the same error when I give the expression without braces {..}. When {} are added, it worked. Below are the steps.
Get MetaData activity is taken and column count is taken as an argument.
Output of MetaData activity:
{
"columnCount": 2,
"effectiveIntegrationRuntime": "AutoResolveIntegrationRuntime (West US)",
"executionDuration": 1,
"durationInQueue": {
"integrationRuntimeQueue": 0
},
"billingReference": {
"activityType": "PipelineActivity",
"billableDuration": [
{
"meterType": "AzureIR",
"duration": 0.016666666666666666,
"unit": "Hours"
}
]
}
}
Then Switch activity is taken and expression and case are given.
Expression: #{activity('Get Metadata1').output.columnCount}
When pipeline is debugged, it got executed successfully without error.