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data intermediate

Merge Data from Multiple Sources

Efficiently combine and reconcile data from multiple sources with structured AI guidance. Perfect for data analysts and business users.

Works with: chatgptclaudegemini

Prompt Template

I need to merge data from multiple sources and need your help creating a comprehensive data integration plan. Please analyze the following information and provide detailed guidance: **Data Sources:** [DATA_SOURCES] **Primary Key/Identifier:** [PRIMARY_KEY] **Expected Output Format:** [OUTPUT_FORMAT] **Specific Challenges:** [CHALLENGES] Please provide: 1. **Data Assessment**: Analyze each source for structure, quality, and potential issues 2. **Merge Strategy**: Recommend the best approach (inner join, outer join, union, etc.) with justification 3. **Key Mapping**: Identify how to match records across sources, including handling of duplicates 4. **Data Cleaning Steps**: List preprocessing steps needed before merging 5. **Conflict Resolution**: How to handle conflicting values for the same entity 6. **Quality Checks**: Validation steps to ensure merge accuracy 7. **Step-by-Step Process**: Detailed implementation steps 8. **Tools/Methods**: Recommend appropriate tools (Excel, SQL, Python, etc.) 9. **Potential Pitfalls**: Common issues to watch for and how to avoid them 10. **Testing Strategy**: How to validate the merged dataset Provide practical, actionable guidance that considers data integrity, completeness, and accuracy throughout the merge process.

Variables to Customize

[DATA_SOURCES]

Description of your data sources including format, size, and key fields

Example: 1) Customer database (CSV, 10k records, fields: customer_id, name, email, phone) 2) Sales transactions (Excel, 50k records, fields: cust_id, product, amount, date) 3) Support tickets (JSON, 5k records, fields: customer_email, issue_type, resolution_date)

[PRIMARY_KEY]

The main identifier to match records across sources

Example: Customer ID (appears as customer_id, cust_id, and need to match by email where ID missing)

[OUTPUT_FORMAT]

Desired structure and format of the merged dataset

Example: Single CSV file with unified customer profiles including demographics, transaction history, and support interactions

[CHALLENGES]

Specific data quality or integration challenges you're facing

Example: Duplicate customer records with slight name variations, missing customer IDs in 20% of transactions, inconsistent date formats across sources

Example Output

## Data Assessment **Source 1 (Customer DB)**: Clean structure, likely primary source for customer info. Potential duplicate names. **Source 2 (Sales)**: Large volume, missing 20% customer IDs requires email matching. **Source 3 (Support)**: JSON format needs flattening, email-only identification. ## Merge Strategy Recommend **Left Join approach** using customer database as master: 1. Start with customer database as foundation 2. Left join sales data on customer_id (direct match) 3. Left join remaining sales via email lookup 4. Left join support tickets via email ## Key Mapping Process - Primary: customer_id ↔ cust_id - Secondary: customer.email ↔ support.customer_email - Create lookup table for email-to-ID mapping ## Data Cleaning Steps 1. Standardize email formats (lowercase, trim) 2. Normalize customer names (title case, remove extra spaces) 3. Convert all dates to YYYY-MM-DD format 4. Handle NULL values consistently ## Conflict Resolution - Customer info conflicts: Prioritize customer database - Use most recent transaction date for tie-breaking - Flag conflicting records for manual review ## Implementation Steps 1. Export all sources to CSV format 2. Create master customer lookup table 3. Perform sequential joins using Excel VLOOKUP or SQL 4. Validate record counts at each step 5. Generate data quality report

Pro Tips for Best Results

  • Always create backups of original data sources before starting the merge process
  • Start with a small sample dataset to test your merge logic before processing the full dataset
  • Document all transformations and mapping rules for future reference and audit trails
  • Use fuzzy matching techniques for names and addresses when exact matches aren't available
  • Implement row-level logging to track which source each merged record came from

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