Table reader

Selects the rows of one database table (or view) and emits them as typed records, one record per row. The row type is generated from the table definition. A DbShapeRequest input adds projection, filtering, sorting and paging. Use it to read reference data or to serve table data to an API.

Pins

Pin	Kind	Types	Description
Input	input	Viaducta.Database.Types.Shaping.DbShapeRequest, Viaducta.TypeSystem.Metadata.AnyData, Viaducta.TypeSystem.Metadata.NoInputData	Triggers the read. Any record works as a trigger; a DbShapeRequest shapes the select.
Output	output	generated <flow namespace>.<TypePrefix><Table>Table	Called once per selected row.
NoData	no-data output	same as input	Called with the input record when the select returns no rows.
Continue	continue output	same as input	Called with the input record after all rows (and after NoData).

Configuration

Field	Type	Default	Description
ConnectionString	database link name		Required. Name of a repository database link (link selector). Looked up by exact name; a raw connection string or #name prefix is not resolved.
TypePrefix	string	Db	Prefix of the generated type name. Triggers reconfigure.
TableName	string (database explorer)		Required. table or schema.table; without a schema the link's default schema is used. Triggers reconfigure.
CommandTimeOut	integer (seconds)	20	Command timeout.
KeepOriginalNames	boolean	false	true keeps column names as property names; false converts them to C# names. Triggers reconfigure.
BatchMode	dropdown: 1 Auto, 2 Always, 3 Never	1	Whether the rows of one read form a batch for batch consumers. Auto: only if the input record is not already in a batch (Timer); a read per record of a batch keeps that batch. Always: a child batch per read. Never: no batch.

Behaviour

• Reconfigure (changing TableName, TypePrefix or KeepOriginalNames) reads the current table definition (never cached, so re-selecting the table picks up schema changes) and generates a locked type named TypePrefix + table name + Table (suffix omitted if the name already ends with Table; the table part converted to a C# name unless KeepOriginalNames). Properties are omitted from JSON when null/default. The type replaces the component's previous types and becomes the only type of Output. A component with its default name is renamed to TRD_<TableName>.
• Renaming the type (prefix, names) changes the type on Output: check the connections behind it.
• Each input runs SELECT of all columns of the table. With a DbShapeRequest input the select uses its Projections (selected columns; * or none means all), Filter (where tree), Sort, Skip and Take (negative Skip/Take is an error). Columns not selected stay at their default value on the record.
• The rows of one read form a batch (BatchMode, opened on the first row): it ends after the last row was processed downstream and before NoData/Continue, so batch consumers (Build array, Bulk insert, Write file) commit then; an error fails it.
• Without connections on Output the table is not read, only Continue is called (the component still starts).
• The status shows Done (N rows). after each read.

Notes

• The component does not poll or mark rows. Every trigger reads the whole table unless a DbShapeRequest filters it.
• The row type is taken from the first Output connection at start; its properties must still match the table columns (start fails otherwise: re-select the table).
• Large tables are streamed row by row, but all downstream components run per row: filter with a shape request or use Sql query for selective reads.

Example

{ "ConnectionString": "MainDb", "TableName": "dbo.Customers", "TypePrefix": "Db", "CommandTimeOut": 30 }

Timer → Table reader → (Output) Data mapper → Http client; (Continue) Log