Get size of view with Expression Rule

Hey - you can think of Appian queries - a!queryEntity() or a!queryRecord() - as being the low-code equivalents of SQL queries. You can, for example, run an a!queryEntity() thaty returns no rows but does return the totalCount based upon your query. Here's a simple example that doesn't apply any filters but does return the totla number of rows for the target entity:

a!queryEntity(
  entity: cons!GIA_DSE_AUDIT,
  query: a!query(
    pagingInfo: a!pagingInfo(
      startIndex: 1,
      batchSize: 0
    )
  ),
  fetchTotalCount: true
)

and the result looks like this:

Hey - you can think of Appian queries - a!queryEntity() or a!queryRecord() - as being the low-code equivalents of SQL queries. You can, for example, run an a!queryEntity() thaty returns no rows but does return the totalCount based upon your query. Here's a simple example that doesn't apply any filters but does return the totla number of rows for the target entity:

a!queryEntity(
  entity: cons!GIA_DSE_AUDIT,
  query: a!query(
    pagingInfo: a!pagingInfo(
      startIndex: 1,
      batchSize: 0
    )
  ),
  fetchTotalCount: true
)

and the result looks like this:

Thank you very much.

I would like to "run" the following query:

SELECT COUNT(*) FROM <table_name>
WHERE <table_name>.<column_name> >= CAST(CURRENT_TIMESTAMP() AS DATE) - INTERVAL 1 DAY

According to your suggestion, I use 

a!queryEntity(
entity: cons!CM_VW_ECHO_CM_CASE,
query: a!query(
pagingInfo: a!pagingInfo(
startIndex: 1,
batchSize: 0
)
),
fetchTotalCount: true
).totalCount

 to count the number of rows.

However, how can I add the condition (where)?

In a Query Entity (as per your example) you will use the 'filter' attribute of a Query Entity to apply the required condition. An individual filter is made up of 3 attributes:

• filed - this maps to the column you're interested in filtering by
• operator - what logical operator you want to apply - in your case it'll be "="
• value - the value you want to apply the operator to - in your case it'll be be something like fn!todate(fn!now() - 1

Note that if your existing table/view has a column of type datetime my example won't work as Appian cannot compare a Date to a Datetime. I think you'd need to create an additional column in your View (I'm guessing it's a view given its prefix in your example!) that is already CAST to Date, and then my example should work