DATA_Code
DATA_Code: TvxClientDataSet
Example
procedure ScriptEvent(var Value: variant);
begin
CreateData(DATA_Code, ['Code,string,100', 'Description,string,200']);
DATA_Code.Append;
DATA_Code['Code'].AsString := 'REF-001';
DATA_Code['Description'].AsString := 'Fictional reference value';
DATA_Code.Post;
Value := DATA_Code.RecordCount;
end;
Usage
DATA_Code provides a general friendly dataset for code lists and other explicitly defined reference working data.
Naming boundary
The current base VxData schema contains several unrelated Code columns and specialised cross-reference tables such as Party_Code; it does not define one universal Code table for this variable. Do not infer a lookup source, key, uniqueness rule or value domain from the identifier. Populate an explicit schema and document what each code means in the calling flow.
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.
Postupdates 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
The generic name is deliberately reusable. Code values from different applications, partners or domains can look identical while having different meanings, so carry the domain or owner in the schema whenever ambiguity matters.
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_Code is a general friendly dataset for code lists or reference rows whose schema is chosen by the script, map or data helper that populates it. 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_Code to TvxActionMan.FData86. Its diagnostic dataset name is DATA_Code.
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
Datasetsexplains cursor, field, edit and ownership rules.CreateDatacreates an explicit in-memory schema.GetDataandGetDataFromDBexplicitly populate a dataset.TvxClientDataSetis the exposed class.
External references
- Embarcadero DocWiki:
TClientDataSetdocuments the inherited Delphi in-memory dataset. - Embarcadero DocWiki:
TDataSetdocuments the inherited cursor and edit model. - Free Pascal:
TDataSetprovides compatibility context; Velox uses Delphi and its own descendant.