Mysql multi-table deletion instance

Mysql multi-table deletion

Delete all the grades of a student while deleting the basic information of the student

Mysql > select * from stu_inf +-- +-+ | id | stu_xh | stu_xm | xb_id | xy_id | stu_bj | + -+ | 1 | 07150101 | Xiao Ming | 1 | 1 | 1504 | | 2 | 07150240 | Xie Yuzheng | 1 | 2 | 1502 | 3 | 12341231 | Monkey | 1 | 2 | 1515 | 4 | 01591261 | Da | 1 | 3 | 1515 | 5 | 07160202 | Xiao Hong | 2 | 4 | 1602 | 6 | 07150225 | Yellow River | 1 | 3 | 1315 | 7 | | | 01050001 | Huarong | 1 | 7 | 1612 | | 8 | 02050002 | Huang Yueying | 2 | 8 | 1608 | 9 | 01510003 | Huanhuan | 2 | 9 | 1601 | | 10 | 05261005 | Dakang | 1 | 10 | 1304 | 13 | 0001 | xxx | 1 | 2 | 1555 | + -+ 11 rows in set (0.02 sec) mysql > select * from cj_inf +-+ | cj_id | cj_stuid | cj_kmid | cj_score | +-+ | 1 | 3 | 1 | 87 | | 2 | 1 | 2 | 65 | | 3 | 4 | 1 | 77 | | 5 | 3 | 9 | 76 | 7 | 1 | 1 | 90 | 15 | 13 | 9 | 90 | 16 | 13 | 8 | 67 | 13 | 13 | 1 | | 88 | +-+ 8 rows in set (0.02 sec) |

Delete statement:

Mysql > DELETE stu_inf,cj_inf from stu_inf LEFT JOIN cj_inf ON stu_inf.id=cj_inf.cj_stuid WHERE stu_inf.id=13;Query OK, 4 rows affected (0.00 sec)

After executing the statement:

Mysql > select * from stu_inf +-- +-+ | id | stu_xh | stu_xm | xb_id | xy_id | stu_bj | + -+ | 1 | 07150101 | Xiao Ming | 1 | 1 | 1504 | | 2 | 07150240 | Xie Yuzheng | 1 | 2 | 1502 | 3 | 12341231 | Monkey | 1 | 2 | 1515 | 4 | 01591261 | Da | 1 | 3 | 1515 | 5 | 07160202 | Xiao Hong | 2 | 4 | 1602 | 6 | 07150225 | Yellow River | 1 | 3 | 1315 | 7 | | 01050001 | Huarong | 1 | 7 | 1612 | | 8 | 02050002 | Huang Yueying | 2 | 8 | 1608 | 9 | 01510003 | Huanhuan | 2 | 9 | 1601 | | 10 | 05261005 | Dakang | 1 | 10 | 1304 | +- -- + 10 rows in set (0.00 sec) mysql > select * from cj_inf +-+ | cj_id | cj_stuid | cj_kmid | cj_score | +-+ | 1 | 3 | 1 | 87 | | 2 | 1 | 2 | 65 | | 3 | 4 | 1 | 77 | | 5 | 3 | 9 | 76 | 7 | 1 | 1 | 90 | +-+ 5 rows in set (0.02 sec)