phpmyadmin - mysql searches the index and finds the key_name of id_2. What index is this? ?

Question

mysql searches the index and finds the key_name of id_2. What index is this? ?
SHOW INDEX FROM spm_works, the result is as shown below:

Answer 1

你应该是你创建的普通索引吧. 给看看 spm_works表的创建语句 : show create table spm_works; 看看有没有创建id_2索引 这行.

Answer 2

id_2这是建立在id字段的索引名称吧，很明显这是普通索引且不唯一。