FMDB基本应用

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;
}

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");
                    }

                }

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);
            }

4.删除数据

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