本文主要是介绍C#实现文件读写到SQLite数据库,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
《C#实现文件读写到SQLite数据库》这篇文章主要为大家详细介绍了使用C#将文件读写到SQLite数据库的几种方法,文中的示例代码讲解详细,感兴趣的小伙伴可以参考一下...
《文件读写到SQLite数据库China编程的方法》博客中,介绍了文件读写到SQLite数据库的方法,例子使用的python语言,本文是使用 C# 将文件读写到 SQLite 数据库的几种方法的具体示例,如果有些概念模糊可参考作者以前博客。
1. 使用 BLOB 存储文件
示例代码:
using System; using System.Data.SQLite; using System.IO; class Program { static void Main(string[] args) { string databasePath = "example.db"; string connectionString = $"Data Source={databGMCMWEYGasePath};Version=3;"; // 创建数据库和表 using (var connection = new SQLiteConnection(connectionString)) { connection.Open(); string createTableQuery = @" CREATE TABLE IF NOT EXISTS Files ( id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, data BLOB NOT NULL );"; using (var command = new SQLiteCommand(createTableQuery, connection)) { command.ExecuteNonQuery(); } } // 插入文件到数据库 string filePath = "example.pdf"; // 替换为你的文件路径 InsertFile(filePath, connectionString); // 从数据库读取文件 ReadFile(1, connectionString); // 假设读取 ID 为 1 的文件 } static void InsertFile(string filePath, string connectionString) { byte[] fileData = File.ReadAllBytes(filePath); string fileName = Path.GetFileName(filePath); using (var connection = new SQLiteConnection(connectionString)) { connection.Open(); string insertQuery = "INSERT INTO Files (name, data) VALUES (@name, @data)"; using (var command = new SQLiteCommand(insertQuery, connection)) { command.Parameters.AddwithValue("@name", fileName); command.Parameters.AddWithValue("@data", fileData); command.ExecuteNonQuery(); } } Console.WriteLine($"File '{fileName}' has been saved to the database."); } static void ReadFile(int fileId, string connectionString) { using (var connection = new SQLiteConnection(connectionString)) { connection.Open(); string selectQuery = "SELECT name, data FROM Files WHERE id = @id"; using (var command = new SQLiteCommand(selectQuery, connection)) { command.Parameters.AddWithValue("@id", fileId); using (var reader = command.ExecuteReader()) { if (reader.Read()) { string fileName = reader.GetString(0); byte[] fileData = (byte[])reader["data"]; File.WriteAllBytes(fileName, fileData); Console.WriteLine($"File '{fileName}' has been restored from the database."); } } } } } }
2. 存储文件路径
示例代码:
using System; using System.Data.SQLite; class Program { static void Main(string[] args) { string databasePath = "example.db"; string connectionString = $"Data Source={databasePath};Version=3;"; // 创建数据库和表 using (var connection = new SQLiteConnection(connectionString)) { connection.Open(); string createTableQuejavascriptry = @" CREATE TABLE IF NOT EXISTS FilePaths ( id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, path TEXT NOT NULL );"; using (var command = new SQLiteCommand(createTableQuery, connection)) { command.ExecuteNonQuery(); } } // 插入文件路径 string filePath = "example.pdf"; // 替换为你的文件路径 InsertFilePath(filePath, connectionString); // 从数据库读取文件路径 GetFilePath(1, connectionString); // 假设读取 ID 为 1 的文件路径 } static void InsertFilePath(string filePath, string connectionString) { string fileName = System.IO.Path.GetFileName(filePath); using (var connection = new SQLiteConnection(connectionString)) { connection.Open(); string insertQuery = "INSERT INTO FilePaths (name, path) VALUES (@name, @path)"; using (var command = new SQLiteCommand(insertQuery, connection)) { command.Parameters.AddWithValue("@name", fileName); command.Parameters.AddWithValue("@path", filePath); command.ExecuteNonQuery()China编程; } } Console.WriteLine($"File path '{filePath}' has been saved to the database."); } static void GetFilePath(int fileId, string connectionString) { using (var connection = new SQLiteConnection(connectionString)) { connection.Open(); string selectQuery = "SELECT name, path FROM FilePaths WHERE id = @id"; using (var command = new SQLiteCommand(selectQuery, connection)) { command.Parameters.AddWithValue("@id", fileId); using (var reader = command.ExecuteReader()) { if (reader.Read()) { string fileName = reader.GetString(0); string filePath = reader.GetString(1); Console.WriteLine($"File '{fileName}' is located at '{filePath}'."); } } } } } }
3. 分块存储文件
示例代码:
using System; using System.Data.SQLite; using System.IO; class Program { static void Main(string[] args) { string databasePath = "example.db"; string connectionString = $"Data Source={databasePath};Version=3;"; // 创建数据库和表 using (var connection = new SQLiteConnection(connectionString)) { connection.Open(); string createTableQuery = @" CREATE TABLE IF NOT EXISTS FileChunks ( id INTEGER PRIMARY KEY AUTOINCREMENT, file_id INTEGER NOT NULL, chunk_index INTEGER NOT NULL, chunk_data BLOB NOT NULL );"; using (var command = new SQLiteCommand(createTableQuery, connection)) { command.ExecuteNonQuery(); } } // 插入文件分块 string filePatGMCMWEYGh = "example.pdf"; // 替换为你的文件路径 InsertFileChunks(filePath, 1, connectionString); // 假设文件 ID 为 1 // 重新组装文件 ReassembleFile(1, "output.pdf", connectionString); // 输出为 output.pdf } static void InsertFileChunks(string filePath, int fileId, string connectionString) { int chunkSize = 1024 * 1024; // 每块大小为 1MB byte[] buffer = new byte[chunkSize]; int chunkIndex = 0; using (var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read)) using (var connection = new SQLiteConnection(connectionString)) { connection.Open(); string insertQuery = "INSERT INTO FileChunks (file_id, chunk_index, chunk_data) VALUES (@file_id, @chunk_index, @chunk_data)"; using (var command = new SQLiteCommand(insertQuery, connection)) { int bytesRead; while ((bytesRead = fileStream.Read(buffer, 0, chunkSize)) > 0) { byte[] chunkData = new byte[bytesRead]; Array.Copy(buffer, chunkData, bytesRead); command.Parameters.Clear(); command.Parameters.AddWithValue("@file_id", fileId); command.Parameters.AddWithValue("@chunk_index", chunkIndex++); command.Parameters.AddWithValue("@chunk_data", chunkData); command.ExecuteNonQuery(); } } } Console.WriteLine($"File '{filePath}' has been stored in chunks."); } static void ReassembleFile(int fileId, string outputPath, string connectionString) { using (var connection = new SQLiteConnection(connectionString)) { connection.Open(); string selectQuery = "SELECT chunk_data FROM FileChunks WHERE file_id = @file_id ORDER BY chunk_index"; using (var command = new SQLiteCommand(selectQuery, connection)) { command.Parameters.AddWithValue("@file_id", fileId); using (var reader = command.ExecuteReader()) using (var outputFile = new FileStream(outputPath, FileMode.Create, FileAccess.Write)) { while (reader.Read()) { byte[] chunkData = (byte[])reader["chunk_data"]; outputFile.Write(chunkData, 0, chunkData.Length); } } } } Console.WriteLine($"File has been reassembled to '{outputPath}'."); } }
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