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duckdb-sql

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DuckDB SQL reference for MotherDuck. Use when you need exact DuckDB syntax, function behavior, supported MotherDuck SQL features, or to resolve whether PostgreSQL-oriented SQL will fail on MotherDuck.

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I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/majiayu000/claude-skill-registry/blob/HEAD/skills/data/duckdb-sql-motherduckdb-agent-skills-2-motherduckdb-agent-skills/SKILL.md

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DuckDB SQL Reference for MotherDuck

Use this skill when you need exact DuckDB syntax, function behavior, or a quick sanity check that a statement will actually work on MotherDuck.

Source Of Truth

  • Prefer current DuckDB SQL docs for language features and function semantics.
  • Use current MotherDuck SQL docs for MotherDuck-only commands such as shares, secrets, snapshots, and Dive operations.
  • If the connection path matters, verify behavior against the current Postgres-endpoint docs before promising server-mode support.

Default Posture

  • Write DuckDB SQL, not PostgreSQL SQL, even when the client connects through the Postgres endpoint.
  • Use fully qualified "database"."schema"."table" names once more than one database or share is in scope.
  • Prefer DuckDB-native constructs when they simplify the query: GROUP BY ALL, QUALIFY, UNION BY NAME, arg_max, EXCLUDE, and REPLACE.
  • Check whether the statement depends on local files, extension install/load, temporary-table behavior, or other client-only features before claiming it will work in MotherDuck.
  • Treat MotherDuck SQL as an additional surface on top of DuckDB SQL, not a replacement for it.

Workflow

  1. Confirm the connection path and whether the question is about syntax, feature support, or a specific error.
  2. Write or repair the statement in DuckDB SQL first.
  3. Verify any MotherDuck-only command or server-mode limitation against the current docs.
  4. If the user needs exact syntax or function details, open references/SYNTAX_REFERENCE.md.

Open Next

  • references/SYNTAX_REFERENCE.md for DuckDB data types, friendly SQL features, functions, complex types, and common MotherDuck-specific gotchas

Related Skills

  • query for writing and validating analytical SQL against live MotherDuck data
  • connect when syntax support depends on PG endpoint versus native DuckDB behavior
  • explore when the problem is really missing schema context rather than missing syntax knowledge