Tableau Transformers

This section documents all deterministic transformers for Tableau Prep nodes.

Available Transformers

1. JoinTransformer - SQL JOINs including anti-joins
2. AggregateTransformer - GROUP BY with aggregations
3. UnionTransformer - UNION ALL with multiple strategies
4. OutputTransformer - SELECT passthrough
5. LoadExcelTransformer - Excel file mapping to tables
6. LoadSqlProxyTransformer - Database table reads
7. ContainerTransformer - Column operations (hybrid with LLM)

Node Type Mapping

Common Features

All Tableau transformers:

• Parse .tfl node metadata
• Handle field sanitization (spaces → underscores)
• Support both sanitized and original field names
• Generate Snowflake-compatible SQL
• Build output schemas from node fields

Field Name Sanitization

Tableau allows field names with spaces and special characters. Transformers handle this with sanitize_output flag:

Original: "Customer Number", "Sales Amount" Sanitized: customer_number, sales_amount

Documentation Format

Each transformer is documented with:

• Overview - What the transformer does
• Capabilities - Features and supported operations
• Tableau Node Example - Real node configuration
• Generated SQL Output - Actual SQL produced
• Output Schema - Resulting field definitions
• Limitations - Known issues and unsupported features

Next Steps

Browse individual transformer documentation for detailed examples and usage.