Update diesel/src/query_builder/combination_clause.rs
@@ -74,6 +74,7 @@ where
#[derive(Debug, Copy, Clone, QueryId)]
/// Computes the set union of the rows returned by the involved `SELECT` statements using SQL `UNION`
pub struct Union;
+
impl<DB: Backend> QueryFragment<DB> for Union {
fn walk_ast(&self, mut out: AstPass<DB>) -> QueryResult<()> {
out.push_sql(" UNION ");
