Rails Postgres ActiveRecord通过查询中的id和自定义数组的交集进行匹配

Question

我的帖子是has_and_belongs_to_many :categories。

我需要这样的东西：

Post.where('here category_ids intersects with custom array [1,2,3]').all

Answer 1

您可以加入类别和查询类别

NSArray *arrayToBeConvertedInToString = @[@"This", @"is", @"an", @"array"];
NSString * result = [[arrayToBeConvertedInToString valueForKey:@"description"] componentsJoinedByString:@" "];
NSLog(@"Array in string: %@", result);