MySQL数据库（16）：高级数据操作-更新数据

update 表名 set 字段名 = 新值 where 判断条件;

update 表名 set 字段名 = 新值 [ where 判断条件 ] limit 数量;
create table my_update(
    id int primary key auto_increment,
    name varchar(10)
);
insert into my_update (name) values ('A'), ('A'), ('A'), ('A');
mysql> select * from my_update;
+----+------+
| id | name |
+----+------+
|  1 | A    |
|  2 | A    |
|  3 | A    |
|  4 | A    |
+----+------+
update my_update set name = 'B' where name = 'A' limit 2;
mysql> select * from my_update;
+----+------+
| id | name |
+----+------+
|  1 | B    |
|  2 | B    |
|  3 | A    |
|  4 | A    |
+----+------+