Skip to main content

DATA_POL

DATA_POL: TvxClientDataSet

Example​

procedure ScriptEvent(var Value: variant);
begin
  CreateData(DATA_OrderLine, ['LineNo,integer', 'ProductCode,string,100', 'Qty,double']);
  DATA_OrderLine.Append;
  DATA_OrderLine['LineNo'].AsInteger := 1;
  DATA_OrderLine['ProductCode'].AsString := 'PRODUCT-001';
  DATA_OrderLine['Qty'].AsFloat := 2;
  DATA_OrderLine.Post;
  Value := DATA_POL.RecordCount;
end;

Usage​

DATA_POL provides a purchase-order-line-oriented alias for the exact same live dataset object as DATA_OrderLine.

Alias and conventional context

The shared object's current convention is the Order_Line shape. The alias does not validate the parent order type, copy the line, bind it to DATA_PO or isolate it from DATA_OrderLine and the later DATA_SOL name.

That convention is guidance for choosing queries and field names, not a guarantee. A configured source/destination or customer extension may expose a different subset or additional columns. Use FindField for optional columns and never assume a named field merely because this page describes the current base schema.

Behaviour, lifecycle and side effects

  • Velox loads all returned rows into memory and preserves fetched string whitespace. Large results can use substantial memory.
  • Field access, navigation, filtering, indexing, inserts, edits, posts and deletes mutate this shared object. Closing or recreating it invalidates retained fields and record positions.
  • Post updates the client dataset; it is not proof of an external database write or transaction commit. SQL or file effects belong to the function used to populate or persist it.
  • Data helper functions generally catch and log SQL or creation failures, potentially leaving the object inactive or reset. Direct invalid field, conversion or dataset-state operations can raise.
  • Action cleanup closes every friendly dataset. Velox owns the object; never free it or depend on records surviving another action execution.
  • The mutable dataset and cursor are not thread-safe. Do not hand the reference to asynchronous work or let nested code reposition it without an explicit contract.

Alias and naming cautions

All schema, query, filter, cursor, edit and close effects are shared with DATA_OrderLine. The header alias DATA_PO points to a different object, so coordinate them using explicit header/line keys.

The friendly suffix never validates record type, authenticates a party or application, enforces foreign keys or prevents the dataset being reused for unrelated data.

Additional Technical Info​

DATA_POL is a compatibility name for the exact live dataset exposed as DATA_OrderLine; it is not a separate purchase-order-line object. It is a live TvxClientDataSet reference; its name does not load data, choose a connection, execute SQL or impose a field layout.

Runtime binding and identity

Velox binds DATA_POL and DATA_OrderLine to the same TvxActionMan.FData26 instance. The object is constructed once with diagnostic dataset name DATA_OrderLine; lower-level errors or logs can therefore use the primary name.

The dataset begins inactive and without fields. CreateData, the Data query helpers and load methods can each replace its current schema and records. Every script using this action sees the same live cursor, filters, indexes and edits until the dataset is closed or repopulated.

Related entries

External references

Created 2026-07-15