fixed: 子查询用到了外部查询的列时，两个列重名没有列名指向的问题。

mybatis-flex-core/src/main/java/com/mybatisflex/core/query/QueryColumn.java

@@ -977,15 +977,17 @@ public class QueryColumn implements CloneSupport<QueryColumn>, Conditional<Query
         // 可以省略表的引用，直接使用列名
         // SELECT 1
         // SELECT id FROM tb_user
-        if (queryTables == null || queryTables.isEmpty() || queryTables.size() == 1) {
+        if (queryTables == null || queryTables.isEmpty()) {
             return null;
         }
 
+        QueryTable consideredTable = queryTables.get(0);
+
         // 列未指定表名，仅以字符串的形式输入列名
         // 以查询表中的第一个表为主
         // SELECT tb_user.id FROM tb_user
         if (selfTable == null) {
-            return queryTables.get(0);
+            return consideredTable;
         }
 
         // 当前表有别名，以别名为主
@@ -994,7 +996,14 @@ public class QueryColumn implements CloneSupport<QueryColumn>, Conditional<Query
             return selfTable;
         }
 
-        QueryTable consideredTable = selfTable;
+        // 当前表没有别名，查询表只有一个
+        // 如果两个表是一样的则可以忽略表的引用
+        // 兼容子查询时，子查询的查询表和父查询没有合并的问题
+        if (queryTables.size() == 1 && Objects.equals(selfTable.name, consideredTable.name)) {
+            return null;
+        }
+
+        consideredTable = selfTable;
 
         // 当前表存在且没有别名
         ListIterator<QueryTable> it = queryTables.listIterator(queryTables.size());

mybatis-flex-test/mybatis-flex-spring-boot-test/src/test/java/com/mybatisflex/test/common/QueryWrapperTest.java

@@ -16,16 +16,23 @@
 
 package com.mybatisflex.test.common;
 
+import com.github.vertical_blank.sqlformatter.SqlFormatter;
 import com.mybatisflex.core.query.CPI;
 import com.mybatisflex.core.query.QueryCondition;
 import com.mybatisflex.core.query.QueryWrapper;
 import com.mybatisflex.core.query.RawQueryTable;
+import com.mybatisflex.test.model.table.RoleTableDef;
+import com.mybatisflex.test.model.table.UserTableDef;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
 import java.util.Arrays;
 
-import static com.mybatisflex.core.query.QueryMethods.*;
+import static com.mybatisflex.core.query.QueryMethods.case_;
+import static com.mybatisflex.core.query.QueryMethods.column;
+import static com.mybatisflex.core.query.QueryMethods.count;
+import static com.mybatisflex.core.query.QueryMethods.distinct;
+import static com.mybatisflex.core.query.QueryMethods.select;
 import static com.mybatisflex.test.model.table.RoleTableDef.ROLE;
 import static com.mybatisflex.test.model.table.UserRoleTableDef.USER_ROLE;
 import static com.mybatisflex.test.model.table.UserTableDef.USER;
@@ -132,4 +139,37 @@ class QueryWrapperTest {
         System.out.println(queryWrapper.toSQL());
     }
 
+    @Test
+    void test05() {
+        RoleTableDef r = ROLE.as("r");
+        UserTableDef u = USER.as("u");
+
+        QueryWrapper queryWrapper = QueryWrapper.create()
+            .select(USER.USER_NAME)
+            .from(USER)
+            .leftJoin(u).on(u.USER_ID.eq(USER.USER_ID))
+            .where(USER.USER_ID.eq(1))
+            // 子查询里面用了父查询里面的表
+            .and(column(select(r.ROLE_ID).from(r).where(u.USER_ID.eq(r.ROLE_ID))).le(2));
+
+        String sql = SqlFormatter.format(queryWrapper.toSQL());
+        System.out.println(sql);
+
+        Assertions.assertEquals("SELECT\n" +
+            "  ` tb_user `.` user_name `\n" +
+            "FROM\n" +
+            "  ` tb_user `\n" +
+            "  LEFT JOIN ` tb_user ` AS ` u ` ON ` u `.` user_id ` = ` tb_user `.` user_id `\n" +
+            "WHERE\n" +
+            "  ` tb_user `.` user_id ` = 1\n" +
+            "  AND (\n" +
+            "    SELECT\n" +
+            "      ` r `.` role_id `\n" +
+            "    FROM\n" +
+            "      ` tb_role ` AS ` r `\n" +
+            "    WHERE\n" +
+            "      ` u `.` user_id ` = ` r `.` role_id `\n" +
+            "  ) <= 2", sql);
+    }
+
 }