Skip to main content

DATA2

DATA2: TvxClientDataSet

Example​

procedure ScriptEvent(var Value: variant);
begin
  CreateData(DATA2, ['Code,string,40', 'Quantity,integer']);
  DATA2.Append;
  DATA2['Code'].AsString := 'SAMPLE-002';
  DATA2['Quantity'].AsInteger := 2;
  DATA2.Post;
  Value := DATA2.RecordCount;
end;

Usage​

DATA2 provides the second independent action-owned client dataset for general script working data.

Behaviour and risks

  • Schema, records, filters, indexes and cursor are mutable state shared by later scripts using DATA2 in the same action execution.
  • DATA2['Field'] raises a dataset-labelled database error when the field is absent. Use FindField for optional columns and do not retain fields across a close/schema replacement.
  • Post changes the in-memory record. Database persistence/commit depends on the separate function and transaction path used.
  • Query/create helpers usually catch and log failures; direct dataset operations can raise. A logged failure can leave the object inactive or reset.
  • Results are fully materialised and the cursor is not thread-safe. Bound large queries and do not share the object with asynchronous work.
  • File operations and query helpers can perform filesystem, database, network or transaction side effects; the variable alone performs none.

DATA1-DATA10 are individually named objects, not array elements. Never free DATA2, infer a table from its number, or rely on records after action cleanup.

Additional Technical Info​

DATA2 is the second of ten independent, action-owned TvxClientDataSet instances for script working data. The name supplies no schema, table, query or business meaning.

Velox creates the object as TvxActionMan.FData2, labels lookup errors DATA2, and binds that same live object into scripters for the action. It starts inactive and unstructured. Use CreateData, a Data query helper or a load method before reading fields; simply referencing it does not fetch data.

Implementation and lifecycle

The Velox descendant preserves string whitespace, disables calculated fields/fetch-on-demand and requests all provider rows. In normal non-edit mode an SQL open copies rows into memory, disables constraints/change logging, detaches the provider and closes the server dataset. Action cleanup closes the dataset, while the object remains owned by the action until destruction.

Related entries

External references

Created 2026-07-15