Data Engineering

DDL to Data Dictionary Generator

Turns CREATE TABLE statements into a Markdown data dictionary, one table per section.

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How to use this tool

  1. Paste one or more CREATE TABLE statements.
  2. Decide whether you want a placeholder left in the description column or an empty cell.
  3. Select Generate dictionary, and copy the Markdown into your wiki or commit it beside the schema.
  4. Fill in the descriptions with someone who knows what the columns mean.

What ddl to data dictionary does

A data dictionary is one of those documents that is obviously worth having and never gets written, because the structural half is tedious to transcribe and the meaningful half needs someone who knows the business. The tedious half is exactly what a machine should do.

This reads the DDL and produces the structural half: every column with its type, nullability, key role and default, laid out as a Markdown table you can paste into a wiki or commit next to the schema. The description column is deliberately left blank, because a definition generated from a column name is not a definition — it is the same name with more words.

Frequently asked questions

Because a description generated from a column name is not a description. It restates the name with more words and gives readers false confidence that the dictionary has been reviewed. The blank cell is honest about what still needs doing.

No. Nothing here connects anywhere. It parses the DDL text you paste and nothing else, which means it is exactly as accurate as the DDL is current.

Standard CREATE TABLE statements with column types, NOT NULL, PRIMARY KEY, UNIQUE, REFERENCES and DEFAULT. Vendor-specific storage clauses and partitioning syntax are ignored rather than misread, so the dictionary stays correct even where it is incomplete.

Yes — the DDL to ERD tool takes the same input and produces a Mermaid entity relationship diagram, and the SQL DDL parser gives you the same information as a table you can filter and export.