diff --git "a/data/2.MySQL\344\270\255\351\230\266/4.\350\201\232\345\220\210\345\222\214\345\210\206\347\273\204/2. \346\261\202\345\222\214/sum.md" "b/data/2.MySQL\344\270\255\351\230\266/4.\350\201\232\345\220\210\345\222\214\345\210\206\347\273\204/2. \346\261\202\345\222\214/sum.md"
index 641180d4901d7df12f64d82db53599ec40f4ec53..c8577bd20cdd450231d13d5f91401684e66f2ce8 100644
--- "a/data/2.MySQL\344\270\255\351\230\266/4.\350\201\232\345\220\210\345\222\214\345\210\206\347\273\204/2. \346\261\202\345\222\214/sum.md"	
+++ "b/data/2.MySQL\344\270\255\351\230\266/4.\350\201\232\345\220\210\345\222\214\345\210\206\347\273\204/2. \346\261\202\345\222\214/sum.md"	
@@ -34,23 +34,17 @@ select sum(total) from orders where deal and unit_price > 1000;
 
 ### A
 
-```sql
-select sum(total) from orders where deal and unit_price > 1000;
-```
-
-### B
-
 ```sql
 select sum(total) from orders having deal and unit_price > 1000;
 ```
 
-### C
+### B
 
 ```sql
 select sum(total) from orders group by deal having unit_price > 1000;
 ```
 
-### D
+### C
 
 ```sql
 select sum(total) from orders having deal and unit_price > 1000;
diff --git "a/data/2.MySQL\344\270\255\351\230\266/4.\350\201\232\345\220\210\345\222\214\345\210\206\347\273\204/3.\346\234\200\345\260\217\345\200\274/min.md" "b/data/2.MySQL\344\270\255\351\230\266/4.\350\201\232\345\220\210\345\222\214\345\210\206\347\273\204/3.\346\234\200\345\260\217\345\200\274/min.md"
index bbf9ce444d24b5e63e910d5a7f8fc5d50b5875ac..2bef6c26aa5d0dab75217da64db9715628614ca3 100644
--- "a/data/2.MySQL\344\270\255\351\230\266/4.\350\201\232\345\220\210\345\222\214\345\210\206\347\273\204/3.\346\234\200\345\260\217\345\200\274/min.md"
+++ "b/data/2.MySQL\344\270\255\351\230\266/4.\350\201\232\345\220\210\345\222\214\345\210\206\347\273\204/3.\346\234\200\345\260\217\345\200\274/min.md"
@@ -38,17 +38,11 @@ select dept, min(salary) from employee;
 ### B
 
 ```sql
-select dept, min(salary) from employee;
+select dept, min(salary) from employee order by dept;
 ```
 
 ### C
 
-```sql
-select dept, min(salary) from employee;
-```
-
-### D
-
 ```sql
 select dept, min(total) from employee;
 ```
\ No newline at end of file
diff --git "a/data/2.MySQL\344\270\255\351\230\266/4.\350\201\232\345\220\210\345\222\214\345\210\206\347\273\204/5. \345\271\263\345\235\207\345\200\274/avg.md" "b/data/2.MySQL\344\270\255\351\230\266/4.\350\201\232\345\220\210\345\222\214\345\210\206\347\273\204/5. \345\271\263\345\235\207\345\200\274/avg.md"
index 35dcd6bf934210257d6840733ef6615c4c6aeea1..9bec946de9e46b326c695a5d5563c1a979709c59 100644
--- "a/data/2.MySQL\344\270\255\351\230\266/4.\350\201\232\345\220\210\345\222\214\345\210\206\347\273\204/5. \345\271\263\345\235\207\345\200\274/avg.md"	
+++ "b/data/2.MySQL\344\270\255\351\230\266/4.\350\201\232\345\220\210\345\222\214\345\210\206\347\273\204/5. \345\271\263\345\235\207\345\200\274/avg.md"	
@@ -38,17 +38,11 @@ select dept, avg(salary) from employee;
 ### B
 
 ```sql
-select dept, avg(salary) from employee;
+select dept, avg(dept) from employee group by dept;
 ```
 
 ### C
 
 ```sql
-select dept, avg(salary) from employee;
+select dept, avg(salary) from employee group by salary;
 ```
-
-### D
-
-```sql
-select dept, avg(salary) from employee ;
-```
\ No newline at end of file
diff --git "a/data/2.MySQL\344\270\255\351\230\266/7. \347\264\242\345\274\225/2.\345\210\233\345\273\272\347\264\242\345\274\225/create_index.md" "b/data/2.MySQL\344\270\255\351\230\266/7. \347\264\242\345\274\225/2.\345\210\233\345\273\272\347\264\242\345\274\225/create_index.md"
index abfe688f17cdaaa3e53fcbea29d83f78a47a4e7f..082df2f1d9c48f1add4028d25f4f5a366e104859 100644
--- "a/data/2.MySQL\344\270\255\351\230\266/7. \347\264\242\345\274\225/2.\345\210\233\345\273\272\347\264\242\345\274\225/create_index.md"	
+++ "b/data/2.MySQL\344\270\255\351\230\266/7. \347\264\242\345\274\225/2.\345\210\233\345\273\272\347\264\242\345\274\225/create_index.md"	
@@ -41,7 +41,7 @@ create unique index idx_goods_category on goods(category_id);
 ### B
 
 ```sql
-create index idx_goods_category on goods(category_id);
+create index idx_goods_category on goods(name);
 ```
 
 ### C