Function import_query 

pub fn import_query<C: SqlConn>(
    conn: C,
    model: &mut Model,
    spec: &ImportSpec,
) -> Result<usize>

Import the result of spec.query into model as a new input measure over the mapped dimension categories. Distinct dimension-column values become items (interned by their string form). Returns the number of cells imported.

SQL data enters purely as input cells (a normal measure collection), so the deterministic engine core is untouched.