mysql8基础 limit 取前三条数据

  •                  OS : Ubuntu 18.04.1 LTS
  •             DBMS : mysql 8.0.12
  •                blog : blog.csdn.net/shiwanwu
  •             github : github.com/GratefulHeartCoder
  •      typesetting : Markdown

数据,数据,命根就在数据 ! 操作数据库时,一定要谨慎小心。师万物 这里的代码看看就好,要有自己的判断。遇到抉择,要不耻上下问。

example

stu@Ubuntu:~$ mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 38
Server version: 8.0.12 MySQL Community Server - GPL

Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> use db_chinese_medicine;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> desc t_fruit;
+--------------+------------------+------+-----+---------+----------------+
| Field        | Type             | Null | Key | Default | Extra          |
+--------------+------------------+------+-----+---------+----------------+
| id           | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| name         | varchar(15)      | NO   | UNI | NULL    |                |
| count        | int(11)          | NO   |     | NULL    |                |
| price        | decimal(6,3)     | NO   |     | NULL    |                |
| is_sales     | tinyint(1)       | NO   |     | 1       |                |
| note         | varchar(255)     | YES  |     ||                |
| gmt_create   | datetime         | NO   |     | NULL    |                |
| gmt_modified | datetime         | NO   |     | NULL    |                |
+--------------+------------------+------+-----+---------+----------------+
8 rows in set (0.01 sec)

mysql> select * from t_fruit;                                                   +----+-----------+-------+--------+----------+------------------------------------+---------------------+---------------------+
| id | name      | count | price  | is_sales | note                               | gmt_create          | gmt_modified        |
+----+-----------+-------+--------+----------+------------------------------------+---------------------+---------------------+
|  1 | 甜瓜      |    10 |  3.210 |        1 || 2018-10-27 19:42:56 | 2018-10-27 19:42:56 |
|  2 | 乌梅      |    20 |  5.430 |        1 || 2018-10-27 19:46:21 | 2018-10-27 19:46:21 |
|  3 | 樱桃      |    30 |  6.540 |        1 || 2018-10-27 19:46:48 | 2018-10-27 19:46:48 |
|  4 | 甘蔗      |    50 |  7.650 |        0 || 2018-10-27 19:51:13 | 2018-10-27 19:51:13 |
|  5 | 菠萝蜜    |    50 |  8.760 |        1 | 菠萝蜜和菠萝是什么关系?            | 2018-10-27 19:55:44 | 2018-10-27 19:55:44 |
|  6 | 无花果    |   100 |  8.760 |        1 || 2018-10-27 19:57:48 | 2018-10-27 19:57:48 |
|  7 | 山葡萄    |   200 |  5.550 |        1 || 2018-10-27 20:11:07 | 2018-10-27 20:11:07 |
|  8 | 无漏子    |     5 |  3.320 |        0 || 2018-10-27 20:11:07 | 2018-10-27 20:11:07 |
|  9 | 五敛子    |    12 |  6.010 |        0 || 2018-10-27 20:11:07 | 2018-10-27 20:11:07 |
| 10 ||    80 | 10.200 |        0 || 2018-10-27 20:11:07 | 2018-10-27 20:11:07 |
+----+-----------+-------+--------+----------+------------------------------------+---------------------+---------------------+
10 rows in set (0.00 sec)

mysql> select * from t_fruit limit 0,3;
+----+--------+-------+-------+----------+------+---------------------+---------------------+
| id | name   | count | price | is_sales | note | gmt_create          | gmt_modified        |
+----+--------+-------+-------+----------+------+---------------------+---------------------+
|  1 | 甜瓜   |    10 | 3.210 |        1 || 2018-10-27 19:42:56 | 2018-10-27 19:42:56 |
|  2 | 乌梅   |    20 | 5.430 |        1 || 2018-10-27 19:46:21 | 2018-10-27 19:46:21 |
|  3 | 樱桃   |    30 | 6.540 |        1 || 2018-10-27 19:46:48 | 2018-10-27 19:46:48 |
+----+--------+-------+-------+----------+------+---------------------+---------------------+
3 rows in set (0.00 sec)

mysql> exit
Bye
stu@Ubuntu:~$ 

resource


MySQL是一个关系型数据库管理系统,目前是开源的(2018-10)。
权限明确,恰当选择引擎与字符集,命名简洁明了与规范。
MariaDB,Redis,MongoDB,PostgreSQL,Hive,HBase等,可以简单地了解。
Workbench,phpMyAdmin,Navicat等图形化管理工具,可以试用一下。

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转载自blog.csdn.net/shiwanwu/article/details/83472635
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