Day: June 19, 2025

alter table information add column English char(6); 1. 修改列的数据类型 假设你有一个表employees，其中有一个列salary，你想将其从DECIMAL(10, 2) 改为DECIMAL(15, 2)。

update information set English=’89’ where no=0001;

MySQL [mydb]> insert into employee values -> (‘李天乐’,’93453′,’34’,’中科院信息技术研究所’); Query OK, 1 row affected (0.090 sec)

MySQL [(none)]> create database mydb; Query OK, 1 row affected (0.093 sec) MySQL [(none)]> use mydb; Database changed MySQL [mydb]> create table employee; ERROR 1113 (42000): A table must have at least 1 column MySQL [mydb]> create table employee\ (name varchar(20) not null, number varchar(10),\ age char(5), department varchar(50)); Query OK, 0 rows affected (0.094… Continue reading create database or table