多线程下的使用

FFDB多线程下的封装也是基于FMDB下的FMDatabaseQueue实现的。 对应在FFDB中，封装成FFDBSafeOperation和FFDBTransaction,两个类的接口都是接近一样的，所以下面的讲解都是根据FFDBTransaction。 在多线程下做任何数据库调用各自的方法都需要放到主线程中执行
❌这是错误的做法：

    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        NSMutableArray *array = [NSMutableArray array];
        for (int i = 0; i<100; i++) {
            ClassRoom *room = [[ClassRoom alloc]init];
            [array addObject:room];
            [FFDBTransaction insertObjectList:array isRollBack:YES completion:nil];
        }
    });

✅这是正确的做法：

    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        NSMutableArray *array = [NSMutableArray array];
        for (int i = 0; i<100; i++) {
            ClassRoom *room = [[ClassRoom alloc]init];
            [array addObject:room];
            [[NSOperationQueue mainQueue]addOperationWithBlock:^{
                [FFDBTransaction insertObjectList:array isRollBack:YES completion:nil];
            }];
        }
    });

1. 插入: 目前提供的方法:

+ (void)insertObjectList:(NSArray <__kindof FFDataBaseModel *>*)objectList
              isRollBack:(BOOL)isRollBack
              completion:(UpdateResult)block;

    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        NSMutableArray *array = [NSMutableArray array];
        for (int i = 0; i<100; i++) {
            ClassRoom *room = [[ClassRoom alloc]init];
            [array addObject:room];
            [[NSOperationQueue mainQueue]addOperationWithBlock:^{
                [FFDBTransaction insertObjectList:array isRollBack:YES completion:nil];
            }];
        }
    });

2. 更新: 目前提供的方法:

+ (void)updateObjectList:(NSArray<__kindof FFDataBaseModel *> *)objectList
              isRollBack:(BOOL)isRollBack
              completion:(UpdateResult)block;

+ (void)updateFromClass:(Class)dbClass
                    set:(NSArray <NSString *>*)setColumns
                  where:(NSString *)whereFormat
                 values:(NSArray <id>*)values
             isRollBack:(BOOL)isRollBack
             completion:(UpdateResult)block;

    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        NSMutableArray *array = [FFDBTransaction selectObjectWithFFDBClass:[ClassRoom class]];
        for (int i = 0; i<array.count; i++) {
            ClassRoom *room = array[i];
            room.name = "I'm update";
            [array addObject:room];
            [[NSOperationQueue mainQueue]addOperationWithBlock:^{
                [FFDBTransaction updateObjectList:array isRollBack:YES completion:nil];
            }];
        }
    });

3. 删除: 目前提供的方法:

+ (void)deleteObjectList:(NSArray<__kindof FFDataBaseModel *> *)objectList
              isRollBack:(BOOL)isRollBack
              completion:(UpdateResult)block;

+ (void)deleteFromClass:(Class)dbClass
                  where:(NSString *)whereFormat
                 values:(NSArray <id>*)values
             isRollBack:(BOOL)isRollBack
             completion:(UpdateResult)block;

    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        NSMutableArray *array = [FFDBTransaction selectObjectWithFFDBClass:[ClassRoom class]];
        for (int i = 0; i<array.count; i++) {
            ClassRoom *room = array[i];
            room.name = "I'm update";
            [array addObject:room];
            [[NSOperationQueue mainQueue]addOperationWithBlock:^{
                [FFDBTransaction deleteObjectList:array isRollBack:YES completion:nil];
            }];
        }
    });

4. 查询

+ (void)selectAllObjectFromClass:(Class)dbClass
                      completion:(QueryResult)block;

+ (void)selectFromClass:(Class)dbClass
                columns:(NSArray <NSString *>*)columns
                  where:(NSString *)whereFormat
                 values:(NSArray <id>*)values
                toClass:(Class)toClass
             completion:(QueryResult)block;

NSMutableArray *array = [FFDBTransaction selectAllObjectFromClass:[ClassRoom class] completion:nil];