## engines.substrait_json()


Compile DuckDB's SQL to a Substrait plan with sverify's lift


Usage

``` python
engines.substrait_json(
    con,
    sql,
    semantics="reference",
)
```


(`sverify.sql_lift`, SQLGlot), as protobuf JSON.

The plan reads the connection's tables by name, and states every choice DuckDB's SQL leaves implicit: casts, output types, function options and sort directions.


## Parameters


`con: Connection`  
The connection whose tables the SQL reads.

`sql: str`  
A query in DuckDB's SQL dialect.

`semantics: str = ``"reference"`  
`"reference"` (the default, as for `sv.verify` and `sv.sql`): what sverify's reference model computes; or `"duckdb"`: what DuckDB computes where the two differ. Before 0.6 the default was `"duckdb"`.


## Returns


`str`  
The Substrait plan as protobuf JSON.


## Raises


`Unsupported`  
The query is outside what the lift reads (a `ValueError`), saying what.