MySQL数据库和表的操作之数据库表操作

数据库表的操作

数据表（table），是一种二维表格，类似于execel，用来存储真正的数据。

创建表格

#语法结构
create table [if not exists] t_name (
    # 定义表结构
    字段名称1 类型 [约束条件],
    字段2  类型 [约束条件],
    ……
    字段n 类型 [约束条件]
);

/**
	创建一个用户表
	用户的姓名
	用户的年龄
	用户的性别
	用户的地址
	用户的电话
**/
create table t_user (
    id int,
    name varchar(50),
    age int,
    gender char(5),
    address varchar(255),
    tel char(11)
);


# 查询表中的数据 
select * from t_name;

# 插入数据
insert into t_name values(1, "duum", 16, '女', "四川成都", "110");

mysql> show tables;
+----------------------+
| Tables_in_db_test |
+----------------------+
| t_name               |
+----------------------+
1 row in set (0.00 sec)

mysql> select * from t_name;
Empty set (0.00 sec)

mysql> describe t_name;
+---------+--------------+------+-----+---------+-------+
| Field   | Type         | Null | Key | Default | Extra |
+---------+--------------+------+-----+---------+-------+
| id      | int          | YES  |     | NULL    |       |
| name    | varchar(50)  | YES  |     | NULL    |       |
| age     | int          | YES  |     | NULL    |       |
| gender  | char(5)      | YES  |     | NULL    |       |
| address | varchar(255) | YES  |     | NULL    |       |
| tel     | char(11)     | YES  |     | NULL    |       |
+---------+--------------+------+-----+---------+-------+
6 rows in set (0.00 sec)

mysql> show create table t_name;
+--------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table  | Create Table

                                                  |
+--------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| t_name | CREATE TABLE `t_name` (
  `id` int DEFAULT NULL,
  `name` varchar(50) DEFAULT NULL,
  `age` int DEFAULT NULL,
  `gender` char(5) DEFAULT NULL,
  `address` varchar(255) DEFAULT NULL,
  `tel` char(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci |
+--------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> show create table t_name\G
*************************** 1. row ***************************
       Table: t_name
Create Table: CREATE TABLE `t_name` (
  `id` int DEFAULT NULL,
  `name` varchar(50) DEFAULT NULL,
  `age` int DEFAULT NULL,
  `gender` char(5) DEFAULT NULL,
  `address` varchar(255) DEFAULT NULL,
  `tel` char(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
1 row in set (0.00 sec)

mysql> insert into t_name values(1, "小度", 16, '女', "四川成都", "120");
Query OK, 1 row affected (0.01 sec)

mysql> select * from t_name;
+------+-----------+------+--------+--------------+------+
| id   | name   | age  | gender | address    | tel  |
+------+-----------+------+--------+--------------+------+
|    1 | 小度    |   16 | 女     | 四川成都     | 120  |
+------+-----------+------+--------+--------------+------+
1 row in set (0.00 sec)

⚠️ 注意：查询sql时，如果结果较多，查看不方便，则可以反正查询的结果，在sql后面加上\G

删除表格

drop table [if exists] t_name;