Method set_set_expr_left_schema

datafusion/sql/src/planner.rs:427–432

Sets the left-most set expression schema, returning the previous value

(
        &mut self,
        schema: Option<DFSchemaRef>,
    )

    /// Sets the left-most set expression schema, returning the previous value
    pub(super) fn set_set_expr_left_schema(
        &mut self,
        schema: Option<DFSchemaRef>,
    ) -> Option<DFSchemaRef> {
        std::mem::replace(&mut self.set_expr_left_schema, schema)
    }
}

/// SQL query planner and binder