RemoveRecordset (Recordset subroutine)

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RemoveRecordset is a member of the Recordset class.

RemoveRecordset &ldquo;NOTs&rdquo; a Recordset object's records with the records in an existing Recordset object: that is, it removes records from the method Recordset object that are in the input Recordset object.

Syntax

%target:RemoveRecordset(recordsetObject)

Syntax terms

%target	A non-null Recordset object variable.
recordsetObject	A non-null Recordset object, which must have the same file context as %target.

Usage Notes

• If the Recordset object argument of RemoveRecordset is null, the request is cancelled.
• Since RemoveRecordset never adds records to a Recordset, there are no lock strength requirements for the method object or the input object.

Examples

• In the following example, the result of one Find is used to eliminate records from the result of another Find.

  %threaten is object recordSet in file orders %bigCust is object recordSet in file orders find records to %threaten status = 'ARREARS' end find find records to %bigCust company ='TOXICO' end find %threaten:removeRecordset(%bigCust)

• RemoveRecordset can be thought of as a NOT operation, AddRecordset as an OR, and AndRecordset as an AND. The missing basic logical operation is an exclusive OR, which is not implemented as a basic method because it is expected to be rarely needed. However, you can achieve such an exclusive OR operation with the provided methods, as in the following example:

  %first is object recordSet in foo %second is object recordSet in foo %both is object recordSet in foo ... %both = %first:copy %both:andRecordset(%second) %first:addRecordset(%second) %first:removeRecordset(%both)

  And %first is now the exclusive OR of the original %first and %second.