How to use result of Lookup Activity in next Lookup of Azure Data Factory? - azure-data-factory

Question

I have Lookup "Fetch Customers" with SQL statement:
Select Count(CustomerId) As 'Row_count' ,Min(sales_amount) as 'Min_Sales' From [sales].
[Customers]
It returns value
10, 5000
Next I have Lookup "Update Min Sales" with SQL statement, but getting error:
Update Sales_Min_Sales
SET Row_Count = #activity('Fetch Customers').output.Row_count,
Min_Sales = #activity('Fetch Customers').output.Min_Sales
Select 1
Same error occurs even I set Lookup to
Select #activity('Fetch Fetch Customers').output.Row_count
Error:
A database operation failed with the following error: 'Must declare the scalar variable
"#activity".',Source=,''Type=System.Data.SqlClient.SqlException,Message=Must declare the
scalar variable "#activity".,Source=.Net SqlClient Data
Provider,SqlErrorNumber=137,Class=15,ErrorCode=-2146232060,State=2,Errors=
[{Class=15,Number=137,State=2,Message=Must declare the scalar variable "#activity".,},],'

Answer 1

I have similar set up as yours. Two lookup activities.
First look up brings min ID and Max ID as shown
{
"count": 1,
"value": [
{
"Min": 1,
"Max": 30118
}
],
"effectiveIntegrationRuntime": "DefaultIntegrationRuntime (East US)",
"billingReference": {
"activityType": "PipelineActivity",
"billableDuration": [
{
"meterType": "AzureIR",
"duration": 0.016666666666666666,
"unit": "DIUHours"
}
]
},
"durationInQueue": {
"integrationRuntimeQueue": 22
}
}
in my second lookup i am using the below expression
Update saleslt.customer set somecol=someval where CustomerID=#{activity('Lookup1').output.Value[0]['Min']}
Select 1 as dummy
Just that we have to access lookup output using indices as mentioned and place the activity output inside {}.