It is possible to use the longtext type to store image data, but it is not recommended. This is because longtext type is mainly used for storing text data, while image data is usually stored in files or databases as byte streams, using longtext type for storage will affect the efficiency of data reading and processing.

For storing image data, it is usually recommended to use the BLOB type, which can store binary data, including images, audio, video and other multimedia data, and can better preserve and manage image data.

In a MySQL database, you can use the BLOB or LONG BLOB type to store large amounts of binary data. the LONG BLOB type allows you to store up to 4GB of data, which is sufficient for most applications.

In short, if you need to store image data, it is recommended to use BLOB or LONG BLOB type to ensure data integrity and read/write efficiency.