wrapper 支持 clear

mybatis-plus-core/src/main/java/com/baomidou/mybatisplus/core/conditions/query/QueryWrapper.java

@@ -47,13 +47,13 @@ public class QueryWrapper<T> extends AbstractWrapper<T, String, QueryWrapper<T>>
     }
 
     public QueryWrapper(T entity) {
-        super.setEntity(entity);
-        super.initNeed();
+        this.setEntity(entity);
+        this.initNeed();
     }
 
     public QueryWrapper(T entity, String... columns) {
-        super.setEntity(entity);
-        super.initNeed();
+        this.setEntity(entity);
+        this.initNeed();
         this.select(columns);
     }
 
@@ -114,4 +114,10 @@ public class QueryWrapper<T> extends AbstractWrapper<T, String, QueryWrapper<T>>
         return new QueryWrapper<>(getEntity(), getEntityClass(), paramNameSeq, paramNameValuePairs, new MergeSegments(),
             SharedString.emptyString(), SharedString.emptyString(), SharedString.emptyString());
     }
+
+    @Override
+    public void clear() {
+        super.clear();
+        sqlSelect.clear();
+    }
 }

mybatis-plus-core/src/main/java/com/baomidou/mybatisplus/core/conditions/update/UpdateWrapper.java

@@ -103,4 +103,10 @@ public class UpdateWrapper<T> extends AbstractWrapper<T, String, UpdateWrapper<T
         return new UpdateWrapper<>(getEntity(), sqlSet, paramNameSeq, paramNameValuePairs, new MergeSegments(),
             SharedString.emptyString(), SharedString.emptyString(), SharedString.emptyString());
     }
+
+    @Override
+    public void clear() {
+        super.clear();
+        sqlSet.clear();
+    }
 }