Add Data Row

Add Data Row

Type: add-row  ·  Package: DataTable Activities v1.0.5  ·  Output: DataRow

Appends a new row at the end of a DataTable and returns the created row.

Modifies the table in place

Unlike most activities in this package (which return a new table), the row/cell operations modify the original table. After Add Data Row, the table you passed has one more row. You don’t need to capture the table in another variable.

How it works

Creates a row with the values you provide and appends it to the table. It returns the created DataRow, so you can keep working on it with Set Cell or Update Data Row.

The values are given in two ways (a toggle in the editor):

• By column — a { column: value } dictionary. Order-independent; each name must be an existing column. Columns you don’t mention are left empty.
• By position — a list of values in column order. You must provide exactly one value per column.

Each value is converted to its column type (for example, "25" to int). A null or an empty string is stored as an empty cell (DBNull). All values are validated before the row is added: if one fails, the table stays as it was.

Required parameters

Parameter	Type	Default	Description
table	DataTable	—	The DataTable the row is added to, e.g. customers.
values	Dictionary | List	—	The row values, by column { column: value } or by position [v1, v2, …]. Each value accepts a literal or an expression.

Optional parameters

None.

Output

Returns the newly created DataRow, already part of the table.

Common errors

Message	Cause and fix
'table' must be a DataTable.	table does not evaluate to a DataTable.
Column '…' does not exist. Available columns: ….	A dictionary key is not a column of the table. The message lists the real columns.
… value(s) provided but the table has … column(s). When passing a list, provide exactly one value per column, in column order.	In by-position mode, the list does not have one value per column. Use null for the ones you want empty.
A value is not compatible with the type '…' of column '…'.	A value cannot be converted to the column type (text in a numeric column, for example). Convert the value first or check the column type.
'values' must be an object { column: value } or a list of values.	values is neither a dictionary nor a list (for example, a plain text).

Example

Build a table and add rows in two ways:

Build DataTable   data: [ { id: 1, name: "Ana", age: 30 } ]   → output: people

Add Data Row   table = people   values (by column): { id: 2, name: "Luis", age: 25 }   → output: row
Add Data Row   table = people   values (by position): [ 3, "Carla", 28 ]

Log   message = "The table has " + rowCount(people) + " rows; the new one belongs to " + str(row["name"])

Clear failure by type

If a value is not compatible with the column type (e.g. text in a numeric column), the activity fails with a clear message stating the column and the expected type — it does not silently store a wrong value.

Related activities

• Build DataTable — create the table to add rows to.
• Set Cell / Update Data Row — modify the returned row.
• Data types › DataRow — what a row is.