在iOS中使用Sqlite数据库登录和注册

import SQLite3

// 数据库文件路径
let dbPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first! + "/myDatabase.sqlite"

// 打开数据库连接
var db: OpaquePointer?
if sqlite3_open(dbPath, &db) == SQLITE_OK {
    // 创建表
    let createTableQuery = "CREATE TABLE IF NOT EXISTS users (id INTEGER PRIMARY KEY AUTOINCREMENT, username TEXT, password TEXT);"
    if sqlite3_exec(db, createTableQuery, nil, nil, nil) == SQLITE_OK {
        print("Table created successfully.")
    } else {
        print("Failed to create table.")
    }
} else {
    print("Failed to open database.")
}

// 注册功能
func register(username: String, password: String) {
    let insertQuery = "INSERT INTO users (username, password) VALUES (?, ?);"
    var statement: OpaquePointer?
    if sqlite3_prepare_v2(db, insertQuery, -1, &statement, nil) == SQLITE_OK {
        sqlite3_bind_text(statement, 1, (username as NSString).utf8String, -1, nil)
        sqlite3_bind_text(statement, 2, (password as NSString).utf8String, -1, nil)
        if sqlite3_step(statement) == SQLITE_DONE {
            print("User registered successfully.")
        } else {
            print("Failed to register user.")
        }
    } else {
        print("Failed to prepare statement.")
    }
    sqlite3_finalize(statement)
}

// 登录功能
func login(username: String, password: String) {
    let selectQuery = "SELECT * FROM users WHERE username = ? AND password = ?;"
    var statement: OpaquePointer?
    if sqlite3_prepare_v2(db, selectQuery, -1, &statement, nil) == SQLITE_OK {
        sqlite3_bind_text(statement, 1, (username as NSString).utf8String, -1, nil)
        sqlite3_bind_text(statement, 2, (password as NSString).utf8String, -1, nil)
        if sqlite3_step(statement) == SQLITE_ROW {
            print("Login successful.")
        } else {
            print("Login failed.")
        }
    } else {
        print("Failed to prepare statement.")
    }
    sqlite3_finalize(statement)
}

// 使用示例
register(username: "john", password: "123456")
login(username: "john", password: "123456")