C#连接SQLite数据库并实现基本操作

string dbFilename =  "test.db";
if (!File.Exists(dbFilename))
{
    SQLiteConnection.CreateFile(dbFilename);
}

string connectionString = string.Format("Data Source={0};Version=3;",dbFilename);
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
    connection.Open();//打开数据库
    connection.ChangePassword("123456");//设置密码
}

string connectionString =string.Format("Data Source={0}; Version=3; Password={1};",dbFilename,"123456");
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
    connection.Open();
}

using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
    connection.Open();
string commandText = "CREATE TABLE IF NOT EXISTS Users (Id INTEGER PRIMARY KEY AUTOINCREMENT, Name VARCHAR(100), Code VARCHAR(100),Password VARCHAR(100))";

using (SQLiteCommand command = new SQLiteCommand(commandText, connection))
    {
        command.ExecuteNonQuery();//执行sql
    }
}

using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
    connection.Open();
string commandText = "insert into Users (Name, Code,Password) values (@name, @code,@password)";
using (SQLiteCommand command = new SQLiteCommand(commandText, connection))
    {
        // 设置参数值
        command.Parameters.AddWithValue("@name", "管理员");
        command.Parameters.AddWithValue("@code", "admin");
        command.Parameters.AddWithValue("@password", "123456");
        // 执行语句
        command.ExecuteNonQuery();
    }
}

using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
    connection.Open();
    string commandText = "update Users SET Password=@password WHERE Code = @code";
    using (SQLiteCommand command = new SQLiteCommand(commandText, connection))
    {
        // 设置参数值
        command.Parameters.AddWithValue("@code", "admin");
        command.Parameters.AddWithValue("@password", "admin123456");
        // 执行语句
        command.ExecuteNonQuery();
    }
}

using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
    connection.Open();
    string commandText  = "select * from Users";
    using (SQLiteCommand command = new SQLiteCommand(commandText, connection))
    {
        using (SQLiteDataReader reader = command.ExecuteReader())
        {
            while (reader.Read())
            {
                Console.WriteLine($"ID: {reader["Id"]}, 名称: {reader["Name"]}, 编码: {reader["Code"]}");
            }
        }
    }
}

using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
    connection.Open();
    string commandText = "delete from  Users where Code = @code";
    using (SQLiteCommand command = new SQLiteCommand(sql, connection))
    {
        // 设置参数值
        command.Parameters.AddWithValue("@code", "admin");
        // 执行语句
        command.ExecuteNonQuery();
    }
}