环境

mysql 5.7

.NET5 控制台项目

特别提一下，使用了Dapper库，因为比较好用

表结构如下图：

.net项目依赖如下：

主要部分代码示例

StringBinary.cs, 将字符串转成二进制，存入；从二进制中取出内容，转为字符串

using System;using System.Collections.Generic;using System.Data;using System.Linq;using System.Text;using System.Threading.Tasks;using Dapper;using MySql.Data.MySqlClient;namespace DapperBinTest{public class StringBinary{public static string str1 = "山高路远沟深，大军纵横驰奔；谁敢横刀立马，唯我彭大将军。";public static int SaveStringByte(){try{using (IDbConnection db = new MySqlConnection(Conn.connStrDefault)){byte[] byteArray = Encoding.Default.GetBytes(str1);var text = str1 + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");string sqlQuery = "Insert Into test1 (text,bin) Values(@text,@bin)";DynamicParameters pars = new DynamicParameters();pars.Add("text", text);pars.Add("bin", byteArray);int rowsAffected = db.Execute(sqlQuery, pars);if (rowsAffected > 0){int pk = db.Query<int>("SELECT LAST_INSERT_ID()").FirstOrDefault();Console.WriteLine($"字符串转二进制插入成功,pk = {pk}");return pk;}return 0;}}catch (Exception e){Console.WriteLine(e.Message);return 0;}}public static void ReadStringByte(int pk){try{using (IDbConnection db = new MySqlConnection(Conn.connStrDefault)){string sqlQuery = $"select * from test1 where id = {pk}";Test1 test1 = db.Query<Test1>(sqlQuery).ToList().FirstOrDefault();if (null != test1){Console.WriteLine($"从mysql读取二进制内容成功, text = {test1.text}, bin.Length = {test1.bin.Length}");string str = Encoding.Default.GetString(test1.bin);Console.WriteLine($"从mysql读取二进制内容成功, text = {test1.text}, bin.Text = {str}");}}}catch (Exception e){Console.WriteLine(e.Message);}}}}

FileBinary.cs 将文件转为二进制，存储；将二进制内容读出，转换为文件存储在本地

using System;using System.Data;using System.IO;using System.Linq;//----引入必要的命名空间using Dapper;using MySql.Data.MySqlClient;namespace DapperBinTest{public class FileBinary{public static string path = @"C:\Users\Administrator\source\repos\DapperBinTest\aaa.jpg";public static int SaveFileByte(){try{using (IDbConnection db = new MySqlConnection(Conn.connStrDefault)){//获取程序根目录例如：F:\\项目源码\\web\bin\Debug\netcoreapp2.2string basePath = AppContext.BaseDirectory;byte[] byteArray = File.ReadAllBytes(path);var text = path + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");string sqlQuery = "Insert Into test1 (text,bin) Values(@text,@bin)";DynamicParameters pars = new DynamicParameters();pars.Add("text", text);pars.Add("bin", byteArray);int rowsAffected = db.Execute(sqlQuery, pars);if (rowsAffected > 0){int pk = db.Query<int>("SELECT LAST_INSERT_ID()").FirstOrDefault();Console.WriteLine($"文件转二进制插入成功,pk = {pk}");return pk;}return 0;}}catch (Exception e){Console.WriteLine(e.Message);return 0;}}public static void ReadFileByte(int pk){try{using (IDbConnection db = new MySqlConnection(Conn.connStrDefault)){string sqlQuery = $"select * from test1 where id = {pk}";Test1 test1 = db.Query<Test1>(sqlQuery).ToList().FirstOrDefault();if (null != test1){Console.WriteLine($"从mysql读取文件内容成功, text = {test1.text}, bin.Length = {test1.bin.Length}");string basePath = AppContext.BaseDirectory;var ext = Path.GetExtension(path);var guid = Guid.NewGuid().ToString();string newPath = bine(basePath, guid + ext);StreamToFile(test1.bin, newPath);Console.WriteLine($"从mysql读取文件内容成功, text = {test1.text}, bin.path = {path}");}}}catch (Exception e){Console.WriteLine(e.Message);}}public static int StreamToFile(byte[] photo, string newPath)//反向转换{byte[] bytes = photo;FileStream fs = new FileStream(newPath, FileMode.Create, FileAccess.Write);fs.Write(bytes, 0, bytes.Length);fs.Flush();fs.Close();return 0;}}}

Main方法，你懂的

namespace DapperBinTest{class Program{static void Main(string[] args){//字符串转二进制，写入mysql//StringBinary.SaveStringByte();//从mysql中读取二进制字符串，并转换为普通字符串//StringBinary.ReadStringByte(13);//文件转为二进制，写入mysql成功//int v = FileBinary.SaveFileByte();//从mysql中读取二进制文件，并转换为普通文件存储到本地。FileBinary.ReadFileByte(14);}}}