在iOS10中使用SQLite3记录

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准备步骤

1. 在项目界面,进入Build Phases面板,选择Link Binary With Libraries --> + --> Add Other... -->Command+Shift+g -->输入/usr/lib --> 选择libsqlite3.dylib
2. 添加一个头文件xxx.h到创建的项目中,打开此文件,输入 #import "sqlite3.h"
3. 在项目界面,进入Build Setting选项,找到Objective-C Bridging Header,将其设置为添加的头文件xxx.h

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示例demo

    var db:OpaquePointer? = nil
    @IBOutlet weak var name: UITextField!
    @IBOutlet weak var address: UITextField!
    @IBOutlet weak var age: UITextField!

Paste_Image.png

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创建数据库

    @IBAction func createdatabse(_ sender: AnyObject) {
        
        let dirPaths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
        let docsDir = dirPaths[0] as NSString
        let databasePath = NSString(string:docsDir.appendingPathComponent("Match.db"))
        
        //判断数据库是否打开
        if (sqlite3_open(databasePath.utf8String, &db) != SQLITE_OK){
            print("数据库打开失败")
        }
        print("数据库路径是:'\(databasePath as String)'")
        sqlite3_close(db)
        
    }

1. 使用sqlite3_open函数打开数据库

2. 使用sqlite3_exec函数执行语句
3. 使用sqlite3_close函数释放资源

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创建表

    func execSql(_ sql:NSString) {
        if sqlite3_exec(db, sql.utf8String, nil, nil, nil) != SQLITE_OK {
            let errmsg = String(cString:sqlite3_errmsg(db))
            print("error creating table :\(errmsg)")
        }
    }

  @IBAction func createtable(_ sender: AnyObject) {
        
        let dirPaths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
        let docsDir = dirPaths[0] as NSString
        let databasePath = NSString(string:docsDir.appendingPathComponent("Match.db"))
        
        //判断数据库是否打开
        if (sqlite3_open(databasePath.utf8String, &db) != SQLITE_OK){
            print("数据库打开失败")
        } else {
            let sqlCreateTable:NSString = NSString(string:"CREATE TABLE IF NOT EXISTS match (name TEXT, address TEXT , age INTEGER)")
            execSql(sqlCreateTable)
            print("创建数据库成功")
        }
        sqlite3_close(db)
    }

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插入数据

    @IBAction func insertData(_ sender: AnyObject) {
        let dirPaths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
        let docsDir = dirPaths[0] as NSString
        let databasePath = NSString(string:docsDir.appendingPathComponent("Match.db"))
        
        if (sqlite3_open(databasePath.utf8String, &db) != SQLITE_OK){
            print("数据库打开失败")
        } else {
            
            let namef = name.text!
            let addressf = address.text!
            let agef = Int(age.text!)!
            
            let sql :NSString = NSString(string: "INSERT  INTO match VALUES ('\(namef)','\(addressf)','\(agef)')")           
            self.execSql(sql)          
            print("插入数据成功")
            
        }
        sqlite3_close(db)
    }

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查询数据

@IBAction func search(_ sender: AnyObject) {
        
        let dirPaths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
        let docsDir = dirPaths[0] as NSString
        let databasePath = NSString(string:docsDir.appendingPathComponent("Match.db"))
        
        var canshu = 33        //查询条件里的整型变量,在本示例暂时固定
        var canshustr = "ttt" //查询条件里的字符串变量,在本示例暂时固定
        var statement:OpaquePointer? = nil

        if (sqlite3_open(databasePath.utf8String, &db) != SQLITE_OK){
            print("数据库打开失败")
        } else { 
            print("数据库打开成功")   
            let sql = "SELECT * FROM match where name = ? and age = ?"
            //let sql = "SELECT * FROM match where age = ?" //单个条件
            //let sql = "SELECT * FROM match" //无查询条件
            let cSql = sql.cString(using: String.Encoding.utf8) //转换为C接受的char*类型
            
            //预处理过程
            if sqlite3_prepare_v2(db, cSql!, -1, &statement, nil) == SQLITE_OK {               
                print("进入预处理过程")         
                //绑定参数开始
                sqlite3_bind_text(statement,1,canshustr,-1,nil) //字符串参数
                sqlite3_bind_int(statement,2,Int32(canshu)) //整型参数
                
                var strname = "a" //简单初始化
                var straddress = "b"
                var strage = 54
                
                //执行查询
                while (sqlite3_step(statement) == SQLITE_ROW) {                 
                    print("开始查询")

                    //提取字段数据
                    if let bufzhudui = UnsafeRawPointer.init(sqlite3_column_text(statement, 0)) {
                        let uptr1 = bufzhudui.bindMemory(to:CChar.self, capacity:0)
                        strname = String(validatingUTF8:uptr1)!
                    }
                    
                    if let bufdate = UnsafeRawPointer.init(sqlite3_column_text(statement, 1)) {
                        let uptr2 = bufdate.bindMemory(to:CChar.self, capacity:0)
                        straddress = String(validatingUTF8:uptr2)!
                    }

                    strage = Int(sqlite3_column_int(statement,2))

                    print("name:'\(strname)'")
                    print("address is :'\(straddress)")
                    print("age is : " + String(strage) )               
                    
                }
                print("查询结束")
                
                sqlite3_finalize(statement)  //释放语句对象

            }            
            
        }
        sqlite3_close(db) //关闭数据库
      
    }

1. 使用sqlite3_open函数打开数据库

2. sqlite3_prepare_v2预处理sql语句 (将sql编译成二进制代码,提高sql语句的执行速度.)
3. sqlite3_bind_text绑定参数(前提:有查询条件)
4. sqlite3_step 执行sql语句,遍历结果集
5. sqlite3_column_text 提取字段数据
6. sqlite3_finalize和sqlite3_close释放资源

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