iOS中如果本地缓存数据库使用的SQLite，绝大数人都使用了FMDB，可以算是标配.如果自己对SQLite原生态的开发方式效率太低，使用FMDB会有种鸟枪换炮的感觉.FMDB相比于原生态的SQLite的查询做出了很多优化，查询更新方法非常简单易用.

FMDB配置

新建Swift项目，下载FMDB项目，将以下四个文件添加至新的项目中:

FlyElephant.png

数据库初始化:
<pre><code>`class DataManager {

static let shareIntance:DataManager = DataManager()

var db:FMDatabase = FMDatabase()

func createDataBase(dataName:String) {
    
    let path:String = NSSearchPathForDirectoriesInDomains(.libraryDirectory, .userDomainMask, true)[0]
    
    let finalPath:String = path.appending("/\(dataName)")
    
    print("数据存储地址:\(finalPath)")
    
    db = FMDatabase(path: finalPath)
    
    if db.open() {
        print("数据库打开成功")
    }
}

}`</code></pre>

订单表中相比之前变化不大，查询方法有所优化:
<pre><code>`class Order {

var db:FMDatabase = DataManager.shareIntance.db

var orderName:String = ""
var orderNumber:Int = 0

// 创建订单表
func createTable()  {
    let createTableSQL = "CREATE TABLE IF NOT EXISTS 't_order' ('id' INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,'orderName' TEXT,'orderNumber' INTEGER);"
    
    let result = db.executeUpdate(createTableSQL, withArgumentsIn: nil)
    
    if result {
        print("创建表格成功")
    }
}

// MARK:- 插入数据
func insertOrder() {
    let insertSQL = "INSERT INTO t_order (orderName, orderNumber) VALUES (\"\(self.orderName)\", \(self.orderNumber));"
    
    let result = db.executeUpdate(insertSQL, withArgumentsIn: nil)
    
    if result {
        print("数据新增成功")
    }
}

func searchData() {
    let querySQL = "SELECT * FROM t_order"
    
    var resultSet:FMResultSet?
    
    do {
        try resultSet =  db.executeQuery(querySQL, values: nil)
        
        while (resultSet?.next())! {
            let name = resultSet?.string(forColumn: "orderName")
            let number = resultSet?.int(forColumn: "orderNumber")
            print("订单编号:\(number!)--订单名称:\(name!)")
        }
    } catch {
        
    }
    
}

func deleteData() {
    let deleteSQL = "DELETE FROM t_order WHERE id = 1"
    
    let result = db.executeUpdate(deleteSQL, withArgumentsIn: nil)
    
    if result {
        print("数据删除成功")
    }
}

func updateData() {
    let updateSQL = "UPDATE t_order SET orderName = '花生' WHERE id = 1"
    
    let result = db.executeUpdate(updateSQL, withArgumentsIn: nil)
    
    if result {
        print("修改成功")
    }
}

}
`</code></pre>

实际测试

关于字段SQL语句网上有很多，基本上差别不大，完全看自己的业务情况，通过简单查询，删除，更新来验证代码:

FlyElephant.png

<pre><code>` override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.

    let dataManager:DataManager = DataManager.shareIntance
    
    dataManager.createDataBase(dataName: "FlyElephant.sqlite")
    
    let order = Order()
    order.createTable()
    
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


@IBAction func addAction(_ sender: UIButton) {
    for i in 0...10 {
        let order:Order = Order()
        order.orderNumber = i
        order.orderName = "FlyElephant-\(i)"
        order.insertOrder()
    }
}

@IBAction func updateAction(_ sender: UIButton) {
    let order:Order = Order()
    order.updateData()
}

@IBAction func searchAction(_ sender: UIButton) {
    let order:Order = Order()
    order.searchData()
}

@IBAction func deleteAction(_ sender: UIButton) {
    let order:Order = Order()
    order.deleteData()
}

`</code></pre>

测试结果如下:

Paste_Image.png