Column Transformer

The Column Transformer processor transforms columns by performing row-based calculations on column values and writing the results to new or existing columns.

To transform columns, you define the name of the column to receive the results of an expression. And then, you use Snowflake SQL to define the expression to use.

You can use Snowflake user-defined functions in Snowflake SQL expressions.

For more information about configuring Snowflake SQL expressions, see Expressions in Pipeline and Stage Properties.

Output Columns

When you configure a Snowflake SQL expression, the Column Transformer processor writes the results of the expression to an output column. You can use an existing column or create a new one.

When you use an existing column, the processor replaces the incoming value with the new value. When you use a new column, the processor adds it to the row and passes the results of the expression.

Configuring a Column Transformer Processor

Configure a Column Transformer processor to perform row-based calculations on column values.

  1. On the General tab, configure the following properties:
    General Property Description
    Name Stage name.
    Description Optional description.
    Cache Data Caches processed data.
  2. On the Column Transformations tab, configure the following properties:
    SQL Expression Property Description
    Output Column Name

    Name of the column to contain the results of the Snowflake SQL expression. Enter the name of a new or existing column as follows: ColumnName.

    If you use an existing column, the processor replaces existing values.

    You can use the asterisk wildcard to represent array indices and map elements.

    SQL Expression Snowflake SQL expression to evaluate.

    Optionally, click Ctrl + Space Bar for help with creating the Snowflake SQL expression.

    For more information about expressions, see Expressions in Pipeline and Stage Properties.
  3. Using simple or bulk edit mode, click the Add icon to add additional Snowflake SQL expressions.