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;

}

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，表

 //删除表

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