fix(join): project build columns for fast returning left join (#19539)

Author: zhang2014

src/query/service/src/pipelines/processors/transforms/new_hash_join/memory/left_join.rs

@@ -111,7 +111,11 @@ impl Join for OuterLeftHashJoin {
                 .map(|x| x.data_type().clone())
                 .collect::<Vec<_>>();
 
-            let build_block = null_block(&types, data.num_rows());
+            let build_block = match null_block(&types, data.num_rows()) {
+                None => None,
+                Some(data_block) => Some(data_block.project(&self.desc.build_projection)),
+            };
+
             let probe_block = Some(data.project(&self.desc.probe_projection));
             let result_block = final_result_block(&self.desc, probe_block, build_block, num_rows);
             return Ok(Box::new(OneBlockJoinStream(Some(result_block))));

tests/sqllogictests/suites/base/03_common/03_0052_join_with_fast_returuning.test

@@ -0,0 +1,33 @@
+query IIII
+with g as (
+    select
+        'sapp'::string as a,
+        'ios'::string as os,
+        to_date('2026-03-02') as week_start,
+        1::decimal(38, 15) as bi_cost
+),
+target as (
+    select
+        week_start,
+        a,
+        os,
+        1.234567890123456::decimal(38, 15) as target_d6_roi
+    from (
+        select
+            'sapp'::string as a,
+            'ios'::string as os,
+            to_date('2026-03-02') as week_start
+    ) t
+    where false
+),
+cte_a as (
+    select g.*, target_d6_roi
+    from g
+    left join target
+        on g.os = target.os
+       and g.week_start = target.week_start
+       and target.a = g.a
+)
+select typeof(target_d6_roi) from cte_a order by week_start;
+----
+DECIMAL(38, 15) NULL