Fix UNKNOWN parameter type error for params used in expressions - #1
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Fix UNKNOWN parameter type error for params used in expressions#1GavinPizza wants to merge 1 commit into
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Parameters used inside an expression (e.g. `WHERE id = $1 + 1`) could not have their type inferred by DuckDB at plan time, failing with "Could not convert DuckDB type: UNKNOWN". Deparse external parameters as CAST($n AS <type>) so DuckDB gets the type Postgres already resolved. Fixes duckdb#480.
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CI validation done (all 8 checks green). Superseded by the upstream PR: duckdb#1062 |
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CI-only PR on the fork to validate the branch before opening the upstream PR against duckdb/pg_duckdb.
A prepared or parameterized statement fails when a bind parameter is used inside an expression, e.g.
SELECT count(*) FROM t WHERE id = $1 + 1:pg_duckdb deparses the query and calls DuckDB
Prepare()at plan time to learn the result types. DuckDB can't infer a parameter's type inside an expression, so it staysUNKNOWNand result-type resolution fails (same root cause as duckdb#396). Since Postgres already resolved the parameter's type, we now deparse each external parameter asCAST($n AS <pgtype>)instead of a bare$n, handing DuckDB the type it needs. A regression test is included.This also changes the error for CTAS-with-a-parameter (still unsupported): the parameter now gets a type, so DuckDB fails later with "Not all parameters were bound" instead of "Could not find parameter with identifier 1" -- same clean failure, different message.
Known limitation:
jsonbparameters still fail (CAST($n AS jsonb)-- DuckDB has nojsonbtype); pre-existing, tracked in duckdb#516.Fixes duckdb#480.