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DATA_SelfLine2

DATA_SelfLine2: TvxClientDataSet

Example​

procedure ScriptEvent(var Value: variant);
begin
  CreateData(DATA_SelfLine2, ['ParentCode,string,100', 'LineNo,integer', 'Description,string,200']);
  DATA_SelfLine2.Append;
  DATA_SelfLine2['ParentCode'].AsString := 'SELF2-001';
  DATA_SelfLine2['LineNo'].AsInteger := 1;
  DATA_SelfLine2['Description'].AsString := 'Second fictional line';
  DATA_SelfLine2.Post;
  Value := DATA_SelfLine2.RecordCount;
end;

Usage​

DATA_SelfLine2 provides a second independent general-purpose line workspace.

Naming boundary

It is not an alias, second row or automatic child of DATA_Self2. The flow decides whether it relates to DATA_Self, DATA_Self2 or another entity and must supply the schema and keys.

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 four Self-family objects are independent mutable cursors. Do not use naming proximity as a substitute for explicit parent/child validation.

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_SelfLine2 is a second independent dataset for a flow-defined line or child projection. 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 constructs the object with the action and binds DATA_SelfLine2 to TvxActionMan.FData9. Its diagnostic dataset name is DATA_SelfLine2.

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