Question

我正在使用DBAccess框架v1.6.12和Xcode 7.2.1。

我想通过指定ID来删除多行。

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

也许，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。但它无法解决。

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，但它只删除了一行。

有效！

毕竟，我写了下面的代码。

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＆＃39; IN（？）＆＃39;查询的样式，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]];

或者你可以在obj-c中使用：

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

如何通过＆＃39; DBAccess＆＃39;删除具有不同ID的多行？ iOS ORM

[追加]

[回复＃1]

1 个答案: