update: 更新此前打不开的图片

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qianguyihao 2023-08-20 17:10:16 +08:00
parent 58c8f9fbe7
commit dbdf9d64a6
2 changed files with 7 additions and 11 deletions

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@ -11,13 +11,13 @@ publish: true
我们可以在 Navicat Premium 软件中,创建数据库和表,然后输入查询命令来查询数据。选择菜单栏「查询->新建查询->输入 sql 命令->运行」即可,效果如下:
![](https://github.com/qianguyihao/Web/blob/master/img/20200417_1750.png)
![](https://img.smyhvae.com/20200417_1750.png)
我们还可以直接在终端输入命令行来操作。
注意,在 Mac 终端执行 sql 命令时,命令的末尾必须加上`;`(英文格式的分号)。效果如下:
![](https://github.com/qianguyihao/Web/blob/master/img/20200417_1700.png)
![](https://img.smyhvae.com/20200417_1700.png)
MySQL 命令行的一些简单命令如下。
@ -225,8 +225,7 @@ SELECT * FROM author INNER JOIN book;
查询结果:
![](https://github.com/qianguyihao/Web/blob/master/img/20200418_2300.png)
![](https://img.smyhvae.com/20200418_2300.png)
上面这种查询,没有意义,因为没有加任何查询条件。
@ -239,8 +238,7 @@ SELECT * FROM author INNER JOIN book ON author.authorId = book.authorId;
查询结果:
![](https://github.com/qianguyihao/Web/blob/master/img/20200418_2305.png)
![](https://img.smyhvae.com/20200418_2305.png)
上面这行命令,跟下面这行命令等价:
@ -256,7 +254,7 @@ SELECT * FROM author LEFT JOIN book ON author.authorId = book.authorId;
查询结果:
![](https://github.com/qianguyihao/Web/blob/master/img/20200418_2310.png)
![](https://img.smyhvae.com/20200418_2310.png)
**情况 3**right join
@ -266,7 +264,7 @@ SELECT * FROM author RIGHT JOIN book ON author.authorId = book.authorId;
查询结果:
![](https://github.com/qianguyihao/Web/blob/master/img/20200418_2315.png)
![](https://img.smyhvae.com/20200418_2315.png)
### 参考链接
@ -285,5 +283,3 @@ SELECT * FROM author RIGHT JOIN book ON author.authorId = book.authorId;

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@ -63,7 +63,7 @@ flush privileges;
针对下面这张表:
![](https://github.com/qianguyihao/Web/blob/master/img/20200418_1728.png)
![](https://img.smyhvae.com/20200418_1728.png)
通过 Node.js可以对其进行一些增删改查操作。代码举例如下。