数据库

 

 

 

 

          

 

 

 

    // 1.打开数据库
    NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"statuses.sqlite"];
    _db = [FMDatabase databaseWithPath:path];
    [_db open];
   
    // 2.创表

    [_db executeUpdate:@"CREATE TABLE IF NOT EXISTS t_status (id integer PRIMARY KEY, status blob NOT NULL, idstr text NOT NULL);"];

 

// 根据请求参数生成对应的查询SQL语句
    NSString *sql = nil;
    if (params[@"since_id"]) {
        sql = [NSString stringWithFormat:@"SELECT * FROM t_status WHERE idstr > %@ ORDER BY idstr DESC LIMIT 20;", params[@"since_id"]];
    } else if (params[@"max_id"]) {
        sql = [NSString stringWithFormat:@"SELECT * FROM t_status WHERE idstr <= %@ ORDER BY idstr DESC LIMIT 20;", params[@"max_id"]];
    } else {
        sql = @"SELECT * FROM t_status ORDER BY idstr DESC LIMIT 20;";
    }
   
    // 执行SQL
    FMResultSet *set = [_db executeQuery:sql];
    NSMutableArray *statuses = [NSMutableArray array];
    while (set.next) {
        NSData *statusData = [set objectForColumnName:@"status"];
        NSDictionary *status = [NSKeyedUnarchiver unarchiveObjectWithData:statusData];
        [statuses addObject:status];

    }

 

// 插入数据