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Delete

procedure Delete(aIndex: Integer)

Example​

procedure ScriptEvent(var Value: variant);
begin
  if not (DATA1.BOF and DATA1.EOF) then
  begin
    // Zero means delete the current record.
    DATA1.Delete(0);
    Value := True;
  end
  else
    Value := False;
end;

Usage​

Moves a relative number of records from the current cursor and deletes the reached record, ignoring an incomplete move.

Errors

Inactive/empty/read-only state, posting/validation failure, navigation events, provider constraints or delete events can raise. A failed move can still have posted prior edits or changed cursor flags before a later delete failure.

Usage notes

Prefer locating a stable business key, verifying it, then calling Delete(0). Use DeleteRecNo only when a transient sequence number is intentionally the contract.

Additional Technical Info​

Delete(aIndex) deletes a record relative to the current cursor. Despite the parameter name, aIndex is not an absolute list/record index.

The example safely selects the only unambiguous form: zero deletes the current record. It is source-reviewed and was not executed by the documentation workflow.

Signature

Implementation

When aIndex <> 0, Velox calls inherited MoveBy(aIndex): positive values move forward and negative values move backward. It discards MoveBy's returned actual distance. It then calls inherited parameterless Delete on whatever record was reached.

If the requested distance crosses EOF/BOF, MoveBy stops at the boundary, sets the corresponding flag and returns a shorter distance. Because that result is ignored, this method proceeds to delete the boundary record rather than rejecting the out-of-range request. Do not pass an unchecked offset.

MoveBy enters browse mode and can post a pending edit before moving. It fires scroll events/notifications. Inherited Delete verifies active/nonempty/writable state, fires delete events, removes the current record, then normally selects the next record or the previous record when the deleted one was last.

Persistence

The method mutates the in-memory client dataset. Normal Velox non-edit activation disables LogChanges, so a delta for ApplyUpdates may not exist. Even when edit-mode change logging is enabled by the host, this call does not itself apply updates or commit an external transaction.

Performance and concurrency

Movement is proportional to the requested/reachable distance in the generic cursor path; deletion/resync cost depends on dataset size/indexes. The operation is destructive and unsynchronised.

External references

Created 2026-07-15