diff --git a/2207/MySQL数据库操作综合练习题答案.md b/2207/MySQL数据库操作综合练习题答案.md
index 87370a8..9f88ed2 100644
--- a/2207/MySQL数据库操作综合练习题答案.md
+++ b/2207/MySQL数据库操作综合练习题答案.md
@@ -114,5 +114,25 @@ CREATE TABLE salary(
 #3添加外键并设置级联更新、级联删除
 ALTER TABLE salary ADD CONSTRAINT fk_sal_eid FOREIGN KEY(empid) 
 REFERENCES employee(empid) ON UPDATE CASCADE ON DELETE CASCADE;
+#4插入记录
+INSERT INTO department()
+VALUES
+(111, '生产部', NULL),
+(222, '销售部', NULL),
+(333, '人事部', NULL);
+
+INSERT INTO employee()
+VALUES
+(1001, '张三', '男', '高级工程师', '1975-1-1', 111),
+(1002, '李四', '女', '助工', '1985-1-1', 111),
+(1003, '王五', '男', '工程师', '1978-11-11', 222),
+(1004, '赵六', '男', '工程师', '1999-1-1', 222);
+
+INSERT INTO salary()
+VALUES
+(1001, 2200, 1100, 200),
+(1002, 1200, 200, NULL),
+(1003, 2900, 700, 200),
+(1004, 1950, 700, 150);
 ```