FMDB 数据库简单用法

落日映苍穹つ 2022-08-09 03:17 163阅读 0赞

Model：

#import <Foundation/Foundation.h>
    
    @interface Player : NSObject
    
    @property(nonatomic,assign) int playerId;
    @property(nonatomic,strong) NSString *playerName;
    @property(nonatomic,strong) NSString *team;
    
    @end

#import "Player.h"
    
    @implementation Player
    
    
    - (NSString *)description{
     
        return [NSString stringWithFormat:@"id->%d-----球员名称->%@---球队名称-->%@",self.playerId,self.playerName,self.team];
    }
    
    
    
    
    @end

DAO：

#import <Foundation/Foundation.h>
    #import "FMDatabase.h"
    #import "FMResultSet.h"
    #import "FMDatabaseQueue.h"
    
    @interface DataManager : NSObject
    
    // 一个单一的SQLite数据库，用于执行SQL语句。
    @property(nonatomic,strong) FMDatabase *dataBase;
    
    // 执行查询一个FMDatabase结果集
    @property(nonatomic,strong) FMResultSet *result;
    
    // 在多个线程来执行查询和更新时会使用这个类。
    @property(nonatomic,strong) FMDatabaseQueue *queue;
    
    
    + (DataManager *)sharedDataManager;
    
    @end

#import "DataManager.h"
    
    
    @implementation DataManager
    
    + (DataManager *)sharedDataManager{
        static DataManager *dataManager = nil;
        static dispatch_once_t  onceToken;
        dispatch_once(&onceToken, ^{
            NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
            NSString *path = [paths objectAtIndex:0];
            NSString *dataPath = [path stringByAppendingPathComponent:@"Player.db"];
            NSLog(@"%@",dataPath);
            FMDatabase *dataBase = [FMDatabase databaseWithPath:dataPath];
            NSString *sql = @"create table if not exists player(id integer primary key autoincrement,playerName text,team text)";
            if ([dataBase open]) {
                [dataBase setShouldCacheStatements:YES];
                [dataBase executeUpdate:sql];
            }else{
                NSLog(@"数据库创建失败");
            }
            dataManager = [[DataManager alloc] init];
            dataManager.dataBase = dataBase;
        });
        return dataManager;
    }
    
    
    
    @end

#import <Foundation/Foundation.h>
    #import "Player.h"
    #import "FMDatabase.h"
    
    @interface PlayerDao : NSObject
    
    @property(nonatomic,strong) FMDatabase *db;
    
    + (PlayerDao *) sharedIntance;
    
    - (BOOL) addPlayer:(Player *)player;
    
    - (BOOL) delPlayer:(Player *)player;
    
    - (BOOL) findPlayer;
    
    - (BOOL) updatePlayer:(Player *)player;
    
    
    
    @end

#import "PlayerDao.h"
    #import "DataManager.h"
    
    #define TABLE  @"player"
    #define PLAYER_NAME @"playerName"
    #define PLAYER_TEAM @"team"
    #define PLAYER_ID @"id";
    
    //需要通过反射形式， 对表结构进行对象化处理不需要自己写太多的  列 这样的名称。    反射处理
    @implementation PlayerDao
    
    - (id)init{
        self = [super init];
        if (self) {
            self.db = [DataManager sharedDataManager].dataBase;
        }
        return self;
    }
    
    + (PlayerDao *) sharedIntance{
        static PlayerDao *playDao;
        static dispatch_once_t onceToken;
        dispatch_once(&onceToken, ^{
            playDao = [[PlayerDao alloc] init];
        });
        return playDao;
    }
    
    - (BOOL) addPlayer:(Player *)player{
        bool  flag;
        NSString *sql = [NSString stringWithFormat:@"insert into %@('%@','%@') values ('%@','%@')",TABLE,PLAYER_NAME,PLAYER_TEAM,player.playerName,player.team];
        if ([self.db open]) {
            flag = [self.db executeUpdate:sql];
        }
        if (flag) {
            NSLog(@"数据插入成功!");
        }
        [self.db close];
        return flag;
    }
    
    - (BOOL) delPlayer:(Player *)player{
        bool  flag;
        NSString *sql = [NSString stringWithFormat:@"delete from %@ where %@ = %d" ,TABLE,@"id",player.playerId];
        if ([self.db open]) {
            flag = [self.db executeUpdate:sql];
        }
        if (flag) {
            NSLog(@"删除成功!");
        }
        [self.db close];
        return flag;
    }
    
    - (BOOL) findPlayer{
        NSMutableArray *array = [[NSMutableArray alloc] init];
        Player *player = nil;
        bool  flag;
        NSString *sql = [NSString stringWithFormat:@"select * from %@",TABLE];
        if ([self.db open]) {
            FMResultSet *result = [self.db executeQuery:sql];
            while ([result next]) {
                int playerId = [result intForColumn:@"id"];
                NSString *playerName = [result stringForColumn:PLAYER_NAME];
                NSString *playerTeam = [result stringForColumn:PLAYER_TEAM];
                player = [[Player alloc] init];
                player.playerName = playerName;
                player.team = playerTeam;
                player.playerId = playerId;
                [array addObject:player];
            }
            for (Player *player in array) {
                NSLog(@"查询数据结果：%@",player);
            }
    
        }
        [self.db close];
        return flag;
        
    }
    
    - (BOOL) updatePlayer:(Player *)player{
        bool  flag;
        NSString *sql = [NSString stringWithFormat:@"update %@  set %@ = '%@' where %@ = '%@' ", TABLE,PLAYER_TEAM,player.team,PLAYER_NAME,player.playerName];
        if ([self.db open]) {
            flag = [self.db executeUpdate:sql];
        }
        if (flag) {
            NSLog(@"修改成功!");
            [self.db close];
        }
        
        return flag;
    }
    
    @end

Controller：

#import "ViewController.h"
    #import "PlayerDao.h"
    #import "Player.h"
    
    @interface ViewController ()
    
    @end
    
    @implementation ViewController
    
    - (void)viewDidLoad {
        [super viewDidLoad];
    }
    
    
    
    
    - (IBAction)add:(id)sender {
        PlayerDao *playDao = [PlayerDao sharedIntance];
        NSLog(@"%@",playDao);
        Player *player = [[Player alloc] init];
        player.playerName = @"詹姆斯";
        player.team = @"东部";
        [playDao addPlayer:player];
    }
    
    - (IBAction)del:(id)sender {
        PlayerDao *playDao = [PlayerDao sharedIntance];
        Player *playe = [[Player alloc] init];
        playe.playerId = 10;
        [playDao delPlayer:playe];
        
    }
    
    - (IBAction)find:(id)sender {
        PlayerDao *playDao = [PlayerDao sharedIntance];
        [playDao findPlayer];
        
    }
    
    - (IBAction)uodate:(id)sender {
        PlayerDao *playDao = [PlayerDao sharedIntance];
        Player *playe = [[Player alloc] init];
        playe.playerName = @"詹姆斯";
        playe.team = @"西部";
        [playDao updatePlayer:playe];
        NSLog(@"%@",playDao);
    }
    
    - (void)didReceiveMemoryWarning {
        [super didReceiveMemoryWarning];
    }
    
    @end

一个表对应一个dao这种形式出来。   FMDB 还是更多的是以jdbc的形式来处理表。 需要打开，关闭这样的处理。   看是否能进行通过实体和表进行来反射出，这种默认的设置太麻烦，后期看改动。