无需查看将数据存储在DB中的代码，我就可以确定问题出在哪里:停止将字符串连接起来以形成ans SQL命令！

请参阅此处:为什么我会得到一个参数无效."从数据库读取图像时出现异常? [

Without looking at your code to store the data in teh DB, I can be pretty sure what the problem is: Stop concatenating strings to form ans SQL command!

See here: Why do I get a "Parameter is not valid." exception when I read an image from my database?[^]