mysql - 多个插入和选择到单个查询中

Question

有没有办法将这种多次插入和选择转换为仅一条语句？

INSERT INTO `subject` (`subject_code`, `student_id`)
   SELECT 'mathematics', student_id FROM student;
INSERT INTO `subject` (`subject_code`, `company_id`)
   SELECT 'science', student_id FROM student;
INSERT INTO `subject` (`subject_code`, `company_id`)
   SELECT 'chemistry', student_id FROM student;

Answer 1

使用union all 或union(取决于你的数据)

INSERT INTO `subject` (`subject_code`, `student_id`)
(SELECT 'mathematics' as subjectcode, student_id FROM student 
union all
SELECT 'science', student_id FROM student 
union all
SELECT 'chemistry', student_id FROM student);