Can mysql save images

MySQL can store images, but it is highly recommended not to do so. As a relational database, MySQL is not suitable for processing unstructured data such as images. Storing images can lead to bloated databases, slow query speed, and difficult backup. The best practice is to store images in a dedicated object storage service and store only image links in MySQL.

Can MySQL save images? The answer is: Yes, but don’t do that!

Many newbies will ask, can MySQL directly store images? On the surface, it's OK. There is a BLOB type in the database, which can stuff a lot of binary data. Isn’t the picture just binary data? So, theoretically, can. But in actual operation, you will find that this thing is a pit, a huge pit that you may not be able to climb out if you fall into it.

Let's review the basics first. MySQL is a relational database that is good at processing structured data, such as names, ages, addresses, etc. in tables. And pictures are essentially a collection of pixels and are unstructured data. Although BLOB can be stored, it goes against the original intention of database design. Just imagine, if you save millions of images in MySQL, what will your database become? It is bloated, the query speed is as slow as a snail, and backup and recovery are even more of a nightmare.

The working principle of BLOB is very simple: it stuffs the binary data of the picture into the database intact. There is no compression, no index, only pure binary streams. Imagine that if you use the SELECT statement to query a picture, the database has to read the entire picture from disk to memory and then pass it back to your application. You know this efficiency. Moreover, the disk I/O pressure on your database server will increase dramatically, directly affecting the performance of other database operations.

Let's take a look at a simple example and demonstrate how to stuff the picture into BLOB :

 <code class="sql">-- 这只是个示意，实际操作中你需要处理文件读取和错误处理CREATE TABLE images ( id INT AUTO_INCREMENT PRIMARY KEY, image BLOB ); -- 假设你已经读取了图片数据到一个变量叫`image_data` INSERT INTO images (image) VALUES (?); -- ? 代表参数，用你的编程语言绑定`image_data`</code>

It looks simple, right? But in actual applications, you have to deal with various exceptions: file reading failure, image format not supported, network interruption, etc. More importantly, you have to consider performance issues. Retrieving pictures, updating pictures, and deleting pictures will all become extremely slow.

More advanced usage? Don't think about it, the advanced usage is not to use this method. There is no so-called "advanced usage" that can solve the performance bottlenecks caused by BLOB storage images.

Common errors? The biggest mistake is to directly use BLOB to store pictures. Other errors, such as forgetting to handle exceptions, forgetting to consider image size limitations, etc., are all small problems, and compared with performance issues, they are not worth mentioning at all. Debugging skills? Use performance analysis tools to look at the I/O load of your database server and you will know what the problem is.

So, what are the best practices? The answer is: use specialized storage services, such as object storage (such as AWS S3, Alibaba Cloud OSS, Azure Blob Storage) . Upload the image to object storage, and then store only the URL of the image in MySQL. In this way, your database will remain lightweight, query speeds quickly, and have excellent scalability. Your app reads the URL from the database and then downloads the image from the object store. This is the correct way to open it.

Remember, databases are used to store structured data. Unstructured data such as pictures are left to professional storage services for processing. This is the kingly way. Don't let your database be the grave of pictures.

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