fix: 修复union 指定别名错误问题

Author: zhou-hao

hsweb-commons/hsweb-commons-crud/src/main/java/org/hswebframework/web/crud/query/QueryAnalyzerImpl.java

@@ -713,6 +713,9 @@ private void initColumns(StringBuilder columns) {
                 columns.append(select.columnList.get(0).owner).append('.').append('*');
                 return;
             }
+            // 判断主表是否是 SelectTable（子查询）
+            boolean isSelectTable = select.table instanceof QueryAnalyzer.SelectTable;
+
             for (Column column : select.columnList) {
                 if ("*".equals(column.name)) {
                     continue;
@@ -727,9 +730,16 @@ private void initColumns(StringBuilder columns) {
                     continue;
                 }
 
+                // 对于 SelectTable（子查询），应该使用列的别名来引用列，而不是原始列名
+                // 因为子查询的列是通过别名暴露给外层查询的
+                String columnName = isSelectTable && column.owner != null
+                    && column.owner.equals(select.table.alias)
+                    ? column.alias  // 使用别名
+                    : column.name;  // 使用原始列名
+
                 columns.append(column.owner)
                        .append('.')
-                       .append(dialect.quote(column.name, column.metadata != null && !column.metadata.realNameDetected()))
+                       .append(dialect.quote(columnName, column.metadata != null && !column.metadata.realNameDetected()))
                        .append(" as ")
                        .append(dialect.quote(column.alias, false));
             }

hsweb-commons/hsweb-commons-crud/src/test/java/org/hswebframework/web/crud/query/QueryAnalyzerImplTest.java

@@ -27,17 +27,17 @@ public void testParamCast() {
         QueryAnalyzerImpl analyzer = new QueryAnalyzerImpl(
             database,
             """
-                  SELECT
-                floor((tb.create_time-?)/?)*?+? as time,
-                count(tb.id) as number
-              FROM s_test tb
-               LEFT JOIN s_test ss ON ss.ID = tb.subsystem_id
-              GROUP BY floor((tb.create_time-?)/?)*?+?
-              """);
+                    SELECT
+                  floor((tb.create_time-?)/?)*?+? as time,
+                  count(tb.id) as number
+                FROM s_test tb
+                 LEFT JOIN s_test ss ON ss.ID = tb.subsystem_id
+                GROUP BY floor((tb.create_time-?)/?)*?+?
+                """);
         SqlRequest request = analyzer.refactor(
             QueryParamEntity
                 .newQuery()
-                .getParam(), 1, 2, 3, 4, 5, 6,7,8);
+                .getParam(), 1, 2, 3, 4, 5, 6, 7, 8);
 
         System.out.println(request.getSql());
         System.out.println(request);
@@ -72,6 +72,8 @@ public void testUnion() {
         QueryAnalyzerImpl analyzer = new QueryAnalyzerImpl(database,
                                                            "select name n from s_test t " +
                                                                "union select name n from s_test t");
+        SqlRequest request = analyzer.refactor(QueryParamEntity.of());
+        System.out.println(request);
 
         assertNotNull(analyzer.select().table.alias, "t");
         assertNotNull(analyzer.select().table.metadata.getName(), "s_test");
@@ -80,6 +82,33 @@ public void testUnion() {
 
     }
 
+
+    @Test
+    public void testUnionColumns() {
+        QueryAnalyzerImpl analyzer = new QueryAnalyzerImpl(
+            database,
+            """
+                select * from (
+                 select name as n from s_test a
+                 union all
+                 select id as n from s_test b
+                ) t
+                """);
+
+
+        SqlRequest request = analyzer.refactor(QueryParamEntity.of());
+
+        System.out.println(request);
+        database.sql()
+            .reactive()
+            .select(request.getSql(),request.getParameters())
+            .then()
+            .as(StepVerifier::create)
+            .expectComplete()
+            .verify();
+
+    }
+
     @Test
     public void test() {
         QueryAnalyzerImpl analyzer = new QueryAnalyzerImpl(database,