Migrate from Data-Add to Data-Correction Schema

This guide explains how to migrate an existing schema built with the Data-Add module to one using the Data-Correction module in WriteBackExtreme. The goal is to shift from a many-to-many mapping model to a precise one-to-one model for better control, traceability, and data integrity.

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Background: Module Differences

Data-Add Module:

• Uses a many-to-many relationship.

• Stores mapping records in the _mapping table in the repository.

• Every new datapoint written creates a new row.

Data-Correction Module:

• Uses a one-to-one relationship.

• Data is written directly into the schema table.

• Enables inline editing and record replacement.

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Why Migrate?

Benefit	Description
Data Integrity	Prevents duplicates by updating existing records.
Traceability	Maps each entry directly to a Tableau datapoint using a unique key.
Simplified Workflow	Removes complexity by eliminating mapping logic for updates.

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Migration Overview

1. Create a new schema using the Data-Correction module.

2. Include all original fields from the Data-Add schema.

3. Add one new column: mapping_key — a unique identifier for Tableau datapoint.

4. Export existing data from the Data-Add schema.

5. Modify the data: Add a mapping_key column in Excel or CSV.

6. Import modified data into the new Data-Correction schema.

7. Update Tableau to use the mapping_key for correction mapping.

Step-by-Step Instructions

1. Create a New Schema

• In the Management Console, create a new schema.

• Select the Data-Correction module.

• Do not base it on the existing Data-Add schema.

2. Add Fields

• Recreate all fields from the original Data-Add schema.

• Add a new column:

  • mapping_key (type: String)

  • This will serve as the primary link to Tableau datapoints.

3. Export Existing Data

• Use the extension to export existing data from the Data-Add schema.

• Alternatively, request a database export from your DBA.

4. Add mapping_key to Your Data

• In Excel/CSV, create a mapping_key column.

• Populate it using a logic that combines one or more fields that identify the Tableau record.

Example:

If you have:

product_id = "ABC123"
country = "US"

Create:

mapping_key = "ABC123_US"

Use a Tableau calculated field that generates the same key.

5. Import into Data-Correction Schema

• Upload the modified data with the mapping_key column.

• Verify all required fields match.

6. Link Tableau to the New Schema

• In Tableau, ensure your dataset includes the same calculated field mapping_key.

• Use it as the identifier field when configuring the extension.

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Field Mapping Example:

Original Data-Add Schema (dataadd_product_pricing_for_countries):

Field	Type
id	UUID
price	Decimal

New Data-Correction Schema (datacorrect_product_pricing_for_countries):

Field	Type
id	UUID
mapping_key	String
price	Decimal

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Important Notes

• mapping_key must be uniquely reproducible in Tableau and your schema.

• Use calculated fields to generate the same value on both sides.

• Be sure the new schema is tested in a staging dashboard before replacing production dashboards.

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For questions or help, contact [email protected].