如何通过 'DBAccess' iOS ORM 删除具有不同 ID 的多行

Question

我在 Xcode 7.2.1.

中使用 DBAccess 框架 v1.6.12

我想通过指定 ID 删除多行。

代码图片：

// MyDataModel is a subclass of DBObject
const int startCount = [[MyDataModel query] count];
NSLog(@"startCount:%@", @(startCount));     // startCount:21

NSString *Ids = [removeIds componentsJoinedByString:@","];
NSLog(@"removingIds:%@", Ids);              // removingIds:48,44,49,45,50,46,51,47,43

DBResultSet *rs = [[[MyDataModel query] whereWithFormat:@"Id in (%@)" withParameters:@[Ids]] fetch];
NSLog(@"resultSetCount:%@", @(rs.count));   // resultSetCount:0
[rs removeAll];

const int afterCount = [[MyDataModel query] count];
NSLog(@"afterCount:%@", @(afterCount));     // afterCount:21

可能是DBAccess不支持"Id in (?,?,?)"格式查询？

请告诉我上面存档的解决方案。

[追加]

当我编写如下代码时，它按预期工作。

这是，将是合法的措施吗？

for (NSNumber *Id in removeIds) {
    [[[[MyDataModel query] whereWithFormat:@"Id = %@" withParameters:@[Id]] fetchLightweight] removeAll];
}

[回复#1]

感谢您的评论。

我试过你的建议。但是无法解决。

NSLog(@"before-delete:%@", @([[MyDataModel query] count]));
  // -> before-delete:23
if (removeIds.count) {
    NSLog(@"removeIds:%@", [removeIds componentsJoinedByString:@","]);
      // -> removeIds:119,120
    [[[[MyDataModel query] whereWithFormat:@"Id in (%@)" withParameters:removeIds] fetchLightweight] removeAll];
}
NSLog(@"after-delete:%@", @([[MyDataModel query] count]));
  // -> after-delete:22
[removeIds enumerateObjectsUsingBlock:^(NSNumber * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
    NSLog(@"Id[%@]=%@", obj, @([[[MyDataModel query] whereWithFormat:@"Id = %@" withParameters:@[obj]] count]));
      // -> Id[119]=0 .. 0 means succeeded to delete
      // -> Id[120]=1 .. 1 means failed to delete
}];

我想删除Id=119和Id=120，但是只删除了一行

成功了！

毕竟下面的代码是我写的

if (removeIds.count) {
    [[[[MyDataModel query] whereWithFormat:@"Id IN (%@)" withParameters:@[removeIds]] fetchLightweight] removeAll];
}

感谢您的帮助！

Answer 1

DBAccess 确实支持 'IN (?)' 查询风格，问题是 ID 应该作为 NSArray 传入。

NSArray* Ids = @[@(12), @(14), @(18)];

DBResultSet *rs = [[[MyDataModel query] whereWithFormat:@"Id IN (%@)" withParameters:@[Ids]];

或者您可以在 obj-c 中使用：

DBResultSet *rs = [[[MyDataModel query] whereWithFormat:@"Id IN (%@)",Ids];

如何通过 'DBAccess' iOS ORM 删除具有不同 ID 的多行

How do I delete multiple rows with different Ids by 'DBAccess' iOS ORM

orm

objective-c

dbaccess

ios

[追加]

[回复#1]