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This usually means ChartDB can’t understand the format of the JSON data you’re providing.Possible Causes:
  • Incorrect JSON Syntax: The JSON data might have syntax errors.
  • Database Client Formatting: Your database client might be outputting JSON in an unrecognized format.
  • Truncated JSON: For large schemas, your database client might cut off the JSON output.
  • Copy-Paste Issues: Errors can be introduced when pasting the JSON into ChartDB.
Troubleshooting Steps:
1

Verify JSON Syntax

Use an online JSON validator to check your exported JSON for syntax errors. Correct any errors found before importing into ChartDB.
2

Adjust Database Client Output Settings (SSMS/Azure Data Studio)

This step is primarily for users using SQL Server Management Studio (SSMS) or Azure Data Studio.
Increase the character limit for query results in your database client:
  1. Go to Tools → Options.
  2. Navigate to Query Results → SQL Server → Results to Text.
  3. Increase Maximum number of characters displayed in each column.
3

Re-export and Re-import

After adjusting settings or correcting JSON syntax, re-run the ChartDB export query. Copy the entire JSON output again and paste it into ChartDB.
4

Try a Different Browser

Test importing the JSON in a different web browser to rule out browser-specific issues.
If your database has multiple schemas, ChartDB might not display all your tables immediately after import.Possible Cause:
  • Default Schema Display: By default, ChartDB only shows tables from the public schema. Tables in other schemas are hidden initially.
Solution:To display tables from other schemas, you need to select them in the schema management panel.Steps:
1

Select Schemas to Display

Go to the tables and fields pages and navigate to the “Managing Schemas” section to learn how to select schemas and display tables from those schemas. Learn more about managing schemas
Users importing PostgreSQL and SQL Server databases sometimes report that relationships between tables are not automatically detected and visualized.Possible Causes:
  • Incomplete Foreign Key Definitions: ChartDB relies on foreign key constraints. If these are missing or incorrect, relationships might not import.
  • Query Limitations (Rare): The import query might not fully capture relationship data in complex schemas.
Troubleshooting Steps:
1

Verify Foreign Key Constraints in your Database

Ensure foreign key constraints are correctly defined in your database. Use a database client to inspect table definitions.
2

Use Updated Import Query

Try using the updated import query provided by the ChartDB team for your specific database.
3

Manually Add Relationships in ChartDB

Create relationships manually within ChartDB using drag and drop, right-click, or the side panel.
4

Check for Naming Conventions

Unconventional naming of foreign key columns might hinder automatic detection.
Sometimes, exporting your diagram to image formats (PNG, JPG, SVG) might fail without a clear error message, or the process might hang.Possible Causes:
  • Diagram Complexity: Very large or complex diagrams can strain browser resources.
  • Browser Limitations: Browser resource limits might prevent successful export.
  • Browser Compatibility: Browser-specific issues might interfere with export.
Troubleshooting Steps:
1

Check Browser Console for Errors

Open your browser’s developer console. Attempt export again. Check the console for JavaScript errors.
2

Try a Different Browser

Try exporting the diagram using a different web browser.
Working with very large database schemas can sometimes lead to performance issues or browser crashes.Possible Causes:
  • Browser Resource Limits: Browsers have resource limitations when rendering large diagrams.
  • ChartDB Optimization: Current ChartDB version is optimized for moderately sized databases.
Recommendations for Handling Large Databases:
1

Import Only Necessary Schemas/Subsets

If possible, import only the schemas or subsets you need to visualize.
2

Simplify Diagrams

Break down very large diagrams into smaller, domain-specific diagrams.
3

Monitor Browser Performance

Observe browser resource usage (CPU, Memory) to identify limitations.
Users sometimes report that their diagrams disappear after closing their browser.
ChartDB cloud version automatically backs up your diagrams in the cloud, while the self-hosted version stores diagrams only in your browser’s local storage and requires manual exports for backup. See our Cloud vs Self-Hosted documentation for more details.
Possible Causes:
  • Browser Data Clearing: Clearing browser data (cache, cookies, site data) can delete locally stored diagrams.
  • Incognito/Private Browsing: Private browsing modes usually clear local storage when the session ends.
  • Browser Settings or Extensions: Some settings or extensions might clear IndexedDB or site data.
Preventing Diagram Loss:
1

Understand Local Browser Storage

Diagrams are stored locally in your web browser.
2

Avoid Clearing Browser Data Unintentionally

Be cautious when clearing browser data. Do not clear “Cookies and other site data” to preserve diagrams.
3

Do Not Use Incognito/Private Browsing for Important Diagrams

Avoid using incognito mode for important diagrams.
4

Regularly Export Your Diagrams as Backups

Regularly export your diagrams as JSON files. Treat these files as backups.