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DATA8

DATA8: TvxClientDataSet

Example​

procedure ScriptEvent(var Value: variant);
begin
  CreateData(DATA8, ['Code,string,40', 'Quantity,integer']);
  DATA8.Append;
  DATA8['Code'].AsString := 'SAMPLE-008';
  DATA8['Quantity'].AsInteger := 8;
  DATA8.Post;
  Value := DATA8.RecordCount;
end;

Usage​

DATA8 provides the eighth independent action-owned client dataset for general script working data.

Behaviour, errors and limits

  • Mutating records, schema, cursor, filters or indexes changes the object seen by later code in the action.
  • A client Post is not a database commit. Persistence is governed by the operation/transaction used.
  • Missing fields and invalid state can raise; query helpers commonly catch/log errors and can leave the dataset inactive.
  • Close/recreate/query operations invalidate retained field and record references.
  • Full result materialisation uses memory proportional to returned data; the cursor is not thread-safe.
  • File and SQL helpers have external effects when called. Never free the Velox-provided object or infer a schema from DATA8.

Additional Technical Info​

DATA8 is the eighth independent, action-owned TvxClientDataSet for temporary or query-backed work. It does not have a built-in table, field set or business purpose.

Velox constructs this distinct object as TvxActionMan.FData82, gives it diagnostic label DATA8, and binds it to the script. The internal slot is non-sequential only because friendly names occupy the intervening action fields.

Implementation and lifecycle

The object begins inactive and without fields. Explicit creation/query/load calls define its current schema and rows. Velox preserves whitespace, disables auto-calculated fields/fetch-on-demand and requests all provider records. Default SQL use copies rows into memory, disables constraints/change logging and detaches/closes the provider-side dataset. Cleanup closes every action dataset after execution.

Related entries

External references

Created 2026-07-15