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[操作系统]FMDB基本使用


1.打开数据库

#import "ViewController.h"#import "FMDB.h"@interface ViewController ()@property (nonatomic, strong) FMDatabase *db;@end@implementation ViewController- (void)viewDidLoad {  [super viewDidLoad];      //打开数据库  [self dbOpen];}/** * 打开数据库 */-(void)dbOpen{  //1.获取数据库文件的路径  NSString *doc=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];    NSString *fileName=[doc stringByAppendingPathComponent:@"toothGroup.sqlite"];    NSLog(@"%@",fileName);      //2.获得数据库  FMDatabase *db=[FMDatabase databaseWithPath:fileName];    //3.打开数据库  if ([db open]) {        //创建表的时候必须要有一个integer类型的,否则创建不成功        NSString *create=@"create table if not exists t_group11(id integer primary key autoincrement,filename text NOT NULL,title text NOT NULL,price text NOT NULL,endTime text NOT NULL)";            BOOL result=[db executeUpdate:create];            if (result) {      NSLog(@"创表成功");    }    else    {      NSLog(@"创表失败");    }      }    self.db=db;}

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2.插入数据

 //往数据库插入数据 缓存数据        if ([self.db open]) {                NSString *sql=[NSString stringWithFormat: @"INSERT INTO t_group11 (filename,title,price,endTime) VALUES('%@','%@','%@','%@')",dict[@"filename"],dict[@"title"],dict[@"price"],dict[@"endTime"]];                    BOOL result=[self.db executeUpdate:sql];                              if (result) {            NSLog(@"插入成功");          }          else          {            NSLog(@"插入失败");          }                  }        

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3.查询数据

 // 1.执行查询语句  FMResultSet *resultSet = [self.db executeQuery:@"SELECT * FROM t_group11"];    // 2.遍历结果    while ([resultSet next]) {         int ID = [resultSet intForColumn:@"id"];            NSString *filename=[resultSet stringForColumn:@"filename"];      NSString *title=[resultSet stringForColumn:@"title"];       NSString *price=[resultSet stringForColumn:@"price"];       NSString *endTime=[resultSet stringForColumn:@"endTime"];              NSLog(@"%d %@ %@ %@ %@", ID, filename, title,price,endTime);      }

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4.删除数据,表

 //删除表      [self.db executeUpdate:@"DROP TABLE IF EXISTS t_group11"];

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