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FILTER ER function

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The FILTER function returns the specified list as a Record list value after the query has been changed so that it filters for the specified condition.

Syntax

FILTER (list, condition)

Arguments

list: Record list

The valid path of a data source of the Record list data type.

condition: Boolean

A valid conditional expression that is used to filter records of the specified list.

Return values

Record list

The resulting list of records.

Usage notes

This function differs from the WHERE function, because the specified condition is applied to any Electronic reporting (ER) data source of the Table records type at the database level. The list and condition can be defined by using tables and relations.

If one or both arguments that are configured for this function (list and condition) don't allow this request to be translated to the direct SQL call, an exception is thrown at design time. This exception informs the user that either list or condition can't be used to query the database.

Note

The FILTER function behaves differently than the WHERE function when the VALUEIN function is used to specify the selection criteria.

  • If the VALUEIN function is used in scope of the WHERE function, and the second argument of VALUEIN refers to a data source that returns no records, the Boolean False value that VALUEIN returns is considered. Therefore, the expression WHERE(Vendors, VALUEIN(Vendors.VendGroup, VendGroups, VendGroups.VendGroup)) returns no vendor records if the VendGroups data source returns no vendor group records.
  • If the VALUEIN function is used in scope of the FILTER function, and the second argument of VALUEIN refers to a data source that returns no records, the Boolean False value that VALUEIN returns is ignored. Therefore, the expression FILTER(Vendors, VALUEIN(Vendors.VendGroup, VendGroups, VendGroups.VendGroup)) returns all vendor records of the Vendors data source, even if the VendGroups data source returns no vendor group records.

Example 1

If Vendor is configured as an ER data source that refers to the VendTable table, the expression FILTER (Vendors, Vendors.VendGroup = "40") returns a list of only vendors that belong to vendor group 40.

Example 2

If Vendor is configured as an ER data source that refers to the VendTable table, and if parmVendorBankGroup is configured as an ER data source that returns a value of the String data type, the expression FILTER ( Vendor.'<Relations'.VendBankAccount, Vendor.'<Relations'.VendBankAccount.BankGroupID = parmVendorBankGroup) returns a list of only vendor accounts that belong to a specific bank group.

Example 3

You enter data source DS of the Calculated field type, and it contains the expression SPLIT ("A,B,C", ","). You then enter another expression, FILTER( DS, DS.Value = "B"). When you try to save this expression in the ER formula designer, the following exception is thrown: "Validation error: The list expression of FILTER function is not queryable."

Additional resources

List functions