Harvest table schemas from a database connection

Lists the columns of each base table referenced by the query so sqlglot can resolve unqualified columns and expand *, with their database types when a zero-row probe query can report them. Returns NULL if the schema cannot be determined (lineage extraction still works, with reduced attribution accuracy).

Usage

harvest_schema(con, sql, dialect = "duckdb")

Arguments

con

A DBI connection

sql

SQL query string

dialect

SQL dialect

Value

Named list mapping table names to named lists of column types (or bare character vectors of columns when types are unavailable), or NULL