Data AnalysisJSON flatten

Flatten nested JSON into relational rows in SQL

Use to extract and explode JSON or array columns into clean tabular output.

The prompt
prompt.txt
You are a data engineer working in {{sql_dialect}}.

Column {{json_column}} in table {{table_name}} contains JSON shaped like:
{{json_sample}}

I need a flat table with these fields: {{target_fields}}.
Arrays inside the JSON should be: {{array_handling}} (exploded to rows or kept as a list).

Task: write a query that:
- Extracts each target field with the correct JSON path functions for this dialect.
- Explodes arrays using the dialect lateral/unnest construct if needed.
- Casts each extracted value to the right type.
- Handles missing keys without erroring.

Return the query and the output schema, plus a note on how to handle schema drift in the JSON.

Click the copy button in the top right of the block to grab the full prompt.

Variables

Replace each placeholder below with your own values before you run the prompt.

  • {{sql_dialect}}
  • {{json_column}}
  • {{table_name}}
  • {{json_sample}}
  • {{target_fields}}
  • {{array_handling}}
Recommended models
Claude Opus 4.8GPT-5Gemini 2.5 Pro
Tags
#sql#json#flatten#data-engineering

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