diff --git a/mysql.sql b/mysql.sql
index 618e8d9..96f4e7f 100644
--- a/mysql.sql
+++ b/mysql.sql
@@ -94,16 +94,17 @@ CREATE TABLE attendance_records
 
 CREATE TABLE major
 (
-    id       INT AUTO_INCREMENT,
-    major_id INT NOT NULL,
+    id       INT AUTO_INCREMENT PRIMARY KEY,
+    major_id VARCHAR(20) NOT NULL UNIQUE,
     major    VARCHAR(255)
 );
 
+
 INSERT INTO major(major_id,major)
-values (000, '计算机科学与技术'),
-       (001, '电子工程'),
-       (002, '经济学'),
-       (003, '生物学');
+values ('000', '计算机科学与技术'),
+       ('001', '电子工程'),
+       ('002', '经济学'),
+       ('003', '生物学');
 
 CREATE TABLE student
 (
@@ -112,7 +113,7 @@ CREATE TABLE student
     student_number VARCHAR(20)  NOT NULL UNIQUE,
     student_name   VARCHAR(255) NOT NULL,
     class_name     VARCHAR(20)  NOT NULL,
-    major_id       INT          NOT NULL,
+    major_id       VARCHAR(20)  NOT NULL,
     FOREIGN KEY (user_id) REFERENCES user (user_id),
     FOREIGN KEY (major_id) REFERENCES major (major_id)
 );