Build DataTable

Build DataTable

Type: build-datatable  ·  Package: DataTable Activities v1.0.0  ·  Output: DataTable

Creates a DataTable from scratch, defining its columns and, optionally, its initial rows. Use it when you need to build a table yourself—to accumulate results, prepare data to write in Excel, or put together a structure to which you will add rows—instead of reading it from a source.

How it works

Define the columns with columns (a list of names) and, if you want, initial rows with rows (a list of rows, each an array of values). The type of each column is deduced from the first non-null value; you can force it with columnTypes.

Required parameters

Parameter	Editor	Description
columns	arreglo	Column names: ["Cliente", "Total"].

Optional parameters

Parameter	Editor	Description
rows	arreglo	Rows as arrays: [["Ana", 100], ["Luis", 200]].
columnTypes	arreglo	Explicit types per column, e.g. ["string", "double"]. If omitted, they are inferred from the first value.

Output

Returns a DataTable with the indicated columns and rows.

Example

Create a table with columns and some initial rows:

Build DataTable
  columns = = arr("Cliente", "Total")
  rows    = = arr(arr("Ana", 100), arr("Luis", 200))
  → output: resumen

Write Excel Sheet   path = "C:/out/resumen.xlsx"   data = = resumen

Build structure before a loop

A common pattern is to create the table with only the columns (without rows) before a For Each, and within the loop generate the data that you then write. To dump a DataTable, Write Excel Sheet and Write CSV receive it directly.

Related activities

• Add Column — add a calculated column to an existing table.
• Read Excel Sheet — get a DataTable from a file.