sql_generation: Fix WHERE clause generation

We're currently only generating `WHERE (TRUE)` and `WHERE (FALSE)`. Fix that.

sql_generation/model/query/select.rs

@@ -229,7 +229,7 @@ impl FromClause {
 
         let mut join_table = JoinTable {
             tables: vec![first_table.clone()],
-            rows: Vec::new(),
+            rows: first_table.rows.clone(),
         };
 
         for join in &self.joins {