fix https://gitee.com/best_handsome/mybatis-plus-join/issues/I6ZANZ

mybatis-plus-join-boot-starter/src/main/java/com/github/yulichang/autoconfigure/MybatisPlusJoinProperties.java

@@ -49,4 +49,9 @@ public class MybatisPlusJoinProperties {
      * 映射查询最大深度
      */
     private int mappingMaxCount = 5;
+
+    /**
+     * 子查询别名
+     */
+    private String subQueryAlias = "st";
 }

mybatis-plus-join-boot-starter/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -49,6 +49,12 @@
       "defaultValue": 5,
       "type": "java.lang.Integer",
       "description": "映射查询最大深度."
+    },
+    {
+      "name": "mybatis-plus-join.sub-query-alias",
+      "defaultValue": "st",
+      "type": "java.lang.String",
+      "description": "子查询表别名."
     }
   ],
   "hints": [

mybatis-plus-join-core/src/main/java/com/github/yulichang/config/ConfigProperties.java

@@ -38,4 +38,8 @@ public class ConfigProperties {
      * TableInfo适配器
      */
     public static ITableInfoAdapter tableInfoAdapter = AdapterHelper.getTableInfoAdapter();
+    /**
+     * 子查询别名
+     */
+    public static String subQueryAlias = "st";
 }

mybatis-plus-join-core/src/main/java/com/github/yulichang/toolkit/TableList.java

@@ -4,6 +4,7 @@ import com.baomidou.mybatisplus.core.toolkit.Assert;
 import com.baomidou.mybatisplus.core.toolkit.CollectionUtils;
 import lombok.Data;
 
+import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
@@ -13,7 +14,12 @@ import java.util.stream.Collectors;
  * @author yulichang
  */
 @Data
-public class TableList {
+public class TableList implements Serializable {
+
+    /**
+     * 上级
+     */
+    private TableList parent;
 
     /**
      * 所有关联的的表
@@ -65,7 +71,7 @@ public class TableList {
             }
             Node node = getByClassFirst(clazz);
             if (Objects.isNull(node)) {
-                return alias;
+                return Objects.isNull(parent) ? alias : parent.getPrefixByClassParent(clazz);
             }
             return node.isHasAlias() ? node.getAlias() : (node.getAlias() + node.getIndex());
         }
@@ -104,7 +110,7 @@ public class TableList {
                     }
                 }
             }
-            return alias;
+            return Objects.isNull(parent) ? alias : parent.getPrefixByClassParent(clazz);
         }
         Node node = getByIndex(index);
         Node dg = dg(node, node.getClazz());
@@ -118,7 +124,7 @@ public class TableList {
             if (list.size() == 1) {
                 Node n = list.get(0);
                 if (n.getClazz() == node.getClazz()) {
-                    return alias;
+                    return Objects.isNull(parent) ? alias : parent.getPrefixByClassParent(clazz);
                 } else {
                     return n.isHasAlias() ? n.getAlias() : (n.getAlias() + n.getIndex());
                 }
@@ -128,9 +134,9 @@ public class TableList {
                         return n.isHasAlias() ? n.getAlias() : (n.getAlias() + n.getIndex());
                     }
                 }
-                return alias;
+                return Objects.isNull(parent) ? alias : parent.getPrefixByClassParent(clazz);
             } else {
-                return alias;
+                return Objects.isNull(parent) ? alias : parent.getPrefixByClassParent(clazz);
             }
         }
     }
@@ -150,7 +156,11 @@ public class TableList {
     public String getPrefixByClass(Class<?> clazz) {
         Node node = getByClassFirst(clazz);
         if (Objects.isNull(node)) {
+            if (Objects.equals(rootClass, clazz)) {
                 return alias;
+            } else {
+                return Objects.isNull(parent) ? alias : parent.getPrefixByClassParent(clazz);
+            }
         } else {
             return node.hasAlias ? node.getAlias() : (node.getAlias() + node.getIndex());
         }
@@ -165,6 +175,21 @@ public class TableList {
         return node.hasAlias ? node.getAlias() : (node.getAlias() + node.getIndex());
     }
 
+    public String getPrefixByClassParent(Class<?> clazz) {
+        if (Objects.equals(clazz, rootClass)) {
+            return alias;
+        }
+        Node node = getByClassFirst(clazz);
+        if (Objects.isNull(node)) {
+            if (Objects.nonNull(parent)) {
+                return parent.getPrefixByClassParent(clazz);
+            } else {
+                return alias;
+            }
+        }
+        return node.hasAlias ? node.getAlias() : (node.getAlias() + node.getIndex());
+    }
+
     private Node getByIndex(int index) {
         return all.stream().filter(i -> i.getIndex() == index).findFirst().orElse(null);
     }
@@ -194,7 +219,7 @@ public class TableList {
     }
 
     @Data
-    public static class Node {
+    public static class Node implements Serializable {
 
         /**
          * 关联表类型

mybatis-plus-join-core/src/main/java/com/github/yulichang/wrapper/MPJLambdaWrapper.java

@@ -4,6 +4,7 @@ import com.baomidou.mybatisplus.core.conditions.SharedString;
 import com.baomidou.mybatisplus.core.conditions.segments.MergeSegments;
 import com.baomidou.mybatisplus.core.toolkit.*;
 import com.baomidou.mybatisplus.core.toolkit.support.SFunction;
+import com.github.yulichang.config.ConfigProperties;
 import com.github.yulichang.toolkit.Constant;
 import com.github.yulichang.toolkit.LambdaUtils;
 import com.github.yulichang.toolkit.TableList;
@@ -183,12 +184,20 @@ public class MPJLambdaWrapper<T> extends MPJAbstractLambdaWrapper<T, MPJLambdaWr
      * 子查询
      */
     public <E, F> MPJLambdaWrapper<T> selectSub(Class<E> clazz, Consumer<MPJLambdaWrapper<E>> consumer, SFunction<F, ?> alias) {
+        return selectSub(clazz, ConfigProperties.subQueryAlias, consumer, alias);
+    }
+
+    /**
+     * 子查询
+     */
+    public <E, F> MPJLambdaWrapper<T> selectSub(Class<E> clazz, String st, Consumer<MPJLambdaWrapper<E>> consumer, SFunction<F, ?> alias) {
         MPJLambdaWrapper<E> wrapper = new MPJLambdaWrapper<E>(null, clazz, SharedString.emptyString(), paramNameSeq, paramNameValuePairs,
                 new MergeSegments(), SharedString.emptyString(), SharedString.emptyString(), SharedString.emptyString(),
                 new TableList(), null, null, null, null) {
         };
-        String st = "st";
         wrapper.tableList.setAlias(st);
+        wrapper.tableList.setRootClass(clazz);
+        wrapper.tableList.setParent(this.tableList);
         wrapper.alias = st;
         wrapper.subTableAlias = st;
         consumer.accept(wrapper);

mybatis-plus-join-core/src/main/java/com/github/yulichang/wrapper/segments/Select.java

@@ -5,13 +5,15 @@ import com.baomidou.mybatisplus.core.toolkit.support.SFunction;
 import com.github.yulichang.wrapper.enums.BaseFuncEnum;
 import org.apache.ibatis.type.TypeHandler;
 
+import java.io.Serializable;
+
 /**
  * 查询列
  *
  * @author yulichang
  * @since 1.3.10
  */
-public interface Select {
+public interface Select extends Serializable {
 
     Class<?> getClazz();
 

mybatis-plus-join-test/test-join/src/test/java/com/github/yulichang/test/join/LambdaWrapperTest.java

@@ -1017,15 +1017,23 @@ class LambdaWrapperTest {
      */
     @Test
     void sub() {
-        ThreadLocalUtils.set("SELECT ( SELECT st.id FROM `user` st WHERE st.del=false AND (st.id <= ?) limit 1 ) AS pid FROM `user` t LEFT JOIN address t1 ON (t1.user_id = t.id) WHERE t.del=false AND t1.del=false AND (t.id <= ?)");
+        ThreadLocalUtils.set("SELECT ( SELECT st.id FROM `user` st WHERE st.del=false AND (st.id = t.id) limit 1 ) AS id FROM `user` t LEFT JOIN address t1 ON (t1.user_id = t.id) WHERE t.del=false AND t1.del=false AND (t.id <= ?)");
         MPJLambdaWrapper<UserDO> wrapper = JoinWrappers.lambda(UserDO.class)
                 .selectSub(UserDO.class, w -> w.select(UserDO::getId)
-                        .le(UserDO::getId, 1000)
+                        .eq(UserDO::getId, UserDO::getId)
-                        .last("limit 1"), UserDO::getPid)
+                        .last("limit 1"), UserDO::getId)
                 .leftJoin(AddressDO.class, AddressDO::getUserId, UserDO::getId)
                 .le(UserDO::getId, 100);
         wrapper.list();
-        System.out.println(1);
+
+        ThreadLocalUtils.set("SELECT ( SELECT st.id FROM address st WHERE st.del=false AND (st.id = t.id) limit 1 ) AS id FROM `user` t LEFT JOIN address t1 ON (t1.user_id = t.id) WHERE t.del=false AND t1.del=false AND (t.id <= ?)");
+        MPJLambdaWrapper<UserDO> wrapper1 = JoinWrappers.lambda(UserDO.class)
+                .selectSub(AddressDO.class, w -> w.select(AddressDO::getId)
+                        .eq(AddressDO::getId, UserDO::getId)
+                        .last("limit 1"), UserDO::getId)
+                .leftJoin(AddressDO.class, AddressDO::getUserId, UserDO::getId)
+                .le(UserDO::getId, 100);
+        wrapper1.list();
     }