diff --git a/src/main/java/com/github/yulichang/wrapper/enums/BaseFuncEnum.java b/src/main/java/com/github/yulichang/wrapper/enums/BaseFuncEnum.java
index 325d9b4..3f04735 100644
--- a/src/main/java/com/github/yulichang/wrapper/enums/BaseFuncEnum.java
+++ b/src/main/java/com/github/yulichang/wrapper/enums/BaseFuncEnum.java
@@ -7,5 +7,8 @@ package com.github.yulichang.wrapper.enums;
  */
 public interface BaseFuncEnum {
 
+    /**
+     * 获取sql 片段
+     */
     String getSql();
 }
diff --git a/src/main/java/com/github/yulichang/wrapper/enums/DefaultFuncEnum.java b/src/main/java/com/github/yulichang/wrapper/enums/DefaultFuncEnum.java
index b0c81ea..ac70fdf 100644
--- a/src/main/java/com/github/yulichang/wrapper/enums/DefaultFuncEnum.java
+++ b/src/main/java/com/github/yulichang/wrapper/enums/DefaultFuncEnum.java
@@ -2,10 +2,12 @@ package com.github.yulichang.wrapper.enums;
 
 /**
  * 常用的sql函数枚举 默认实现
- * 可以自己实现 {@link BaseFuncEnum} 自定义函数
+ * 可以自己实现接口 {@link BaseFuncEnum} 自定义函数
  * 目前支持一个占位符,不支持多个%s
  * <p>
  * 只例举几个通用的,其他函数 first() last() len() ucase() lcase() 等 或者数据库自定义函数请自行扩展
+ * <p> mpj的初衷是只针对简单的连表查询,而非相对复杂的查询,
+ * <p> 建议慎用,复杂的查询还是推荐写sql
  *
  * @author yulichang
  */
diff --git a/src/main/java/com/github/yulichang/wrapper/interfaces/Query.java b/src/main/java/com/github/yulichang/wrapper/interfaces/Query.java
index 3ca76c2..e68edd6 100644
--- a/src/main/java/com/github/yulichang/wrapper/interfaces/Query.java
+++ b/src/main/java/com/github/yulichang/wrapper/interfaces/Query.java
@@ -4,6 +4,7 @@ import com.baomidou.mybatisplus.core.metadata.TableFieldInfo;
 import com.baomidou.mybatisplus.core.toolkit.support.SFunction;
 import com.github.yulichang.toolkit.LambdaUtils;
 import com.github.yulichang.wrapper.enums.BaseFuncEnum;
+import com.github.yulichang.wrapper.enums.DefaultFuncEnum;
 
 import java.io.Serializable;
 import java.util.function.Predicate;
@@ -13,6 +14,7 @@ import java.util.function.Predicate;
  *
  * @author yulichang
  */
+@SuppressWarnings("unused")
 public interface Query<Children> extends Serializable {
 
     /**
@@ -47,15 +49,6 @@ public interface Query<Children> extends Serializable {
     <S> Children selectAs(SFunction<S, ?> column, String alias);
 
 
-    default <S, X> Children selectFunc(BaseFuncEnum funcEnum, SFunction<S, ?> column) {
-        return selectFunc(funcEnum, column, column);
-    }
-
-
-    default <S, X> Children selectFunc(BaseFuncEnum funcEnum, SFunction<S, ?> column, SFunction<X, ?> alias) {
-        return selectFunc(funcEnum, column, LambdaUtils.getName(alias));
-    }
-
     /**
      * 聚合函数查询
      *
@@ -65,6 +58,15 @@ public interface Query<Children> extends Serializable {
      */
     <S> Children selectFunc(BaseFuncEnum funcEnum, SFunction<S, ?> column, String alias);
 
+    default <S> Children selectFunc(BaseFuncEnum funcEnum, SFunction<S, ?> column) {
+        return selectFunc(funcEnum, column, column);
+    }
+
+
+    default <S, X> Children selectFunc(BaseFuncEnum funcEnum, SFunction<S, ?> column, SFunction<X, ?> alias) {
+        return selectFunc(funcEnum, column, LambdaUtils.getName(alias));
+    }
+
     default <X> Children selectFunc(BaseFuncEnum funcEnum, Object column, SFunction<X, ?> alias) {
         return selectFunc(funcEnum, column, LambdaUtils.getName(alias));
     }
@@ -75,4 +77,120 @@ public interface Query<Children> extends Serializable {
      * select sql 片段
      */
     String getSqlSelect();
+
+    /* 默认聚合函数扩展 */
+
+    /**
+     * SUM()
+     */
+    default <S> Children selectSum(SFunction<S, ?> column) {
+        return selectFunc(DefaultFuncEnum.SUM, column);
+    }
+
+    default <X> Children selectSum(Object column, SFunction<X, ?> alias) {
+        return selectFunc(DefaultFuncEnum.SUM, column, alias);
+    }
+
+    default Children selectSum(Object column, String alias) {
+        return selectFunc(DefaultFuncEnum.SUM, column, alias);
+    }
+
+    default <S, X> Children selectSum(SFunction<S, ?> column, SFunction<X, ?> alias) {
+        return selectFunc(DefaultFuncEnum.SUM, column, alias);
+    }
+
+    /**
+     * COUNT()
+     */
+    default <S> Children selectCount(SFunction<S, ?> column) {
+        return selectFunc(DefaultFuncEnum.COUNT, column);
+    }
+
+    default <X> Children selectCount(Object column, SFunction<X, ?> alias) {
+        return selectFunc(DefaultFuncEnum.COUNT, column, alias);
+    }
+
+    default Children selectCount(Object column, String alias) {
+        return selectFunc(DefaultFuncEnum.COUNT, column, alias);
+    }
+
+    default <S, X> Children selectCount(SFunction<S, ?> column, SFunction<X, ?> alias) {
+        return selectFunc(DefaultFuncEnum.COUNT, column, alias);
+    }
+
+    /**
+     * MAX()
+     */
+    default <S> Children selectMAX(SFunction<S, ?> column) {
+        return selectFunc(DefaultFuncEnum.MAX, column);
+    }
+
+    default <X> Children selectMAX(Object column, SFunction<X, ?> alias) {
+        return selectFunc(DefaultFuncEnum.MAX, column, alias);
+    }
+
+    default Children selectMAX(Object column, String alias) {
+        return selectFunc(DefaultFuncEnum.MAX, column, alias);
+    }
+
+    default <S, X> Children selectMAX(SFunction<S, ?> column, SFunction<X, ?> alias) {
+        return selectFunc(DefaultFuncEnum.MAX, column, alias);
+    }
+
+    /**
+     * MIN()
+     */
+    default <S> Children selectMIN(SFunction<S, ?> column) {
+        return selectFunc(DefaultFuncEnum.MIN, column);
+    }
+
+    default <X> Children selectMIN(Object column, SFunction<X, ?> alias) {
+        return selectFunc(DefaultFuncEnum.MIN, column, alias);
+    }
+
+    default Children selectMIN(Object column, String alias) {
+        return selectFunc(DefaultFuncEnum.MIN, column, alias);
+    }
+
+    default <S, X> Children selectMIN(SFunction<S, ?> column, SFunction<X, ?> alias) {
+        return selectFunc(DefaultFuncEnum.MIN, column, alias);
+    }
+
+    /**
+     * MIN()
+     */
+    default <S> Children selectAVG(SFunction<S, ?> column) {
+        return selectFunc(DefaultFuncEnum.AVG, column);
+    }
+
+    default <X> Children selectAVG(Object column, SFunction<X, ?> alias) {
+        return selectFunc(DefaultFuncEnum.AVG, column, alias);
+    }
+
+    default Children selectAVG(Object column, String alias) {
+        return selectFunc(DefaultFuncEnum.AVG, column, alias);
+    }
+
+    default <S, X> Children selectAVG(SFunction<S, ?> column, SFunction<X, ?> alias) {
+        return selectFunc(DefaultFuncEnum.AVG, column, alias);
+    }
+
+    /**
+     * LEN()
+     */
+    default <S> Children selectLEN(SFunction<S, ?> column) {
+        return selectFunc(DefaultFuncEnum.LEN, column);
+    }
+
+    default <X> Children selectLEN(Object column, SFunction<X, ?> alias) {
+        return selectFunc(DefaultFuncEnum.LEN, column, alias);
+    }
+
+    default Children selectLEN(Object column, String alias) {
+        return selectFunc(DefaultFuncEnum.LEN, column, alias);
+    }
+
+    default <S, X> Children selectLEN(SFunction<S, ?> column, SFunction<X, ?> alias) {
+        return selectFunc(DefaultFuncEnum.LEN, column, alias);
+    }
 }