更改表的插入值

Question

disease_category

cat_id      cat_name            sub_id          sub_name 

1         Infect Disease           1             head   
1         Infect Disease           2            development de

how to alter the sub_name development de into development delay?

how to insert new column C_id as primary key & auto_increment ?

Answer 1

how to alter the sub_name development de into development delay?

Answer :You need to use update query.

update tablename
set sub_name='development delay'
where sub_name='development de'

2nd question:

ALTER TABLE tablename ADD c_id INT PRIMARY KEY AUTO_INCREMENT;