ids

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: i'm trying to execute this query : Code: this.getHibernateTemplate() find("select distinct ci.customer " + "from CustomerInvoice ci " + "where ci.id in (?) " , ids); with ids as a List, id is of type Long when executing i get exception Code: java.lang.ClassCastException: java.util.ArrayList cannot be cast to java.lang.Long at org.hibernate.type.LongType.set(LongType.java:42) at org.hibernate.type.NullableType.nullSafeSet(NullableType.java:136) at org.hibernate.type.NullableType.nullSafeSet(NullableType.java:116) at org.hibernate.param

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: Running the following query using PDO (Actually, I use prepared statements but same problem) INSERT INTO MyTable(MyField) VALUES('Row1'), ('Row2') How can I get the Ids for the records relating to Row1 and Row2 ? $db->lastInsertId() literally returns the last single Id. Is it sufficient to take this last Id, subtract the # of records and assume that range covers all my records? can there be gaps/jumps. Is this query guaranteed to be atomic? 回答1: If you're using MyISAM tables then because of the table level locking mechanism it's only

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: We want to obtain an auto-increment ID from mySQL without actually storing it until the other non-mysql related processes are successfully completed, so that the entry is not stored if an exception or application crash happens. We need to use the ID as a key for the other processes. In essence we want to “reserve” the auto-increment and insert the rows into mySQL as the last step. We don’t want to insert any row until we know the entire process has completed successfully. Is it possible to do this sort of auto-increment reservation in mySQL?

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: In a Many to Many relation between two table with a Mapping table in between, how can I only load ids for the second entity. Following is the example to explain what I want to achieve here. Below is a sample schema create table user( id int PrimaryKey, name text ) create table pages ( id int PrimaryKey, page_name text ) create table user_page ( id_user int, id_page int, PrimaryKey (id_user, id_page) ) Note: there are additional columns in user and page tables which i have not included here for brevity. User entity: @Entity @Table(name =

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: Using the standard route: config.Routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); With these actions: public class ValuesController : ApiController { // GET api/values public string GetAll() { return "all"; } // GET api/values/5 public string GetById(int id) { return "single"; } // GET api/values?ids=1&ids=2 public string GetByIds([FromUri] int[] ids) { return "multiple"; } And make a request to /api/values , I get this exception: Multiple actions were found

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: I use only classes and never use IDs. Many people like to use IDs for different reasons. I've seen many questions regarding IDs vs classes on stackoverflow, but no one addressed pure code organization point of view disregarding compatibility and runtime performance. From code organization point of view, I think that using IDs is bad just like using global variables in Visual Basic code. One reason is that IDs have to be unique which introduces unnecessary and bad dependency between different independent parts of your code

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm using Django 1.7.7. I'm wondering if anyone has experienced this. This is my query: events = Event.objects.filter( Q(date__gt=my_date) | Q(date__isnull=True) ).filter(type__in=[...]).order_by('date') When I try to then paginate it p = Paginator(events, 10) p.count # Gives 91 event_ids = [] for i in xrange(1, p.count / 10 + 2): event_ids += [i.id for i in p.page(i)] print len(event_ids) # Still 91 print len(set(event_ids)) # 75 I noticed that if I removed the .order_by , I don't get any duplicates. I then tried just .order_by with Event

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have a list of different ids, start dates and end dates, let's say : [ (5, d.datetime(2010, 9, 19, 0, 0, 0), d.datetime(2010, 9, 19, 0, 5, 10)), (6, d.datetime(2010, 9, 19, 0, 0, 0), d.datetime(2010, 9, 19, 12, 59, 59)), (4, d.datetime(2010, 9, 19, 10, 30, 17), d.datetime(2010, 9, 19, 20, 20, 59)), (6, d.datetime(2010, 9, 19, 14, 12, 0), d.datetime(2010, 9, 19, 23, 59, 59)), (5, d.datetime(2010, 9, 19, 17, 0, 22), d.datetime(2010, 9, 19, 19, 14, 20)) ] I need somehow to find overlapping timerange and prepare new list with properly ids

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: The Goal In my preferences.xml I would like to store the ID of certain string elements (like) e.g. ... <string-array name="preference_values"> <item>@string/nav_start</item> <item>@string/nav_overview</item> <item>@string/nav_someelse</item> </string-array> ... meanwhile in xml/pref_general.xml ... <ListPreference android:key="@string/preference_key" android:entryValues="@array/preference_values" ... /> ... where the different strings will be localized: Since I don't want to store the localized strings (as those xml definitions do right now)

Impala 性能调整 下面的章节介绍影响 Impala 功能性能的各种因素，并对 Impala 查询和其他 SQL 操作进行性能调整、监控和基准测试。 这一章节同样描述了最大化 Impala 可扩展性的技术。可扩展性与性能相关：它意味着当系统负载增加时仍保持高性能(Scalability is tied to performance: it means that performance remains high as the system workload increases)。例如，减少查询的硬盘 I/O 可以加快单个的查询，与此同时，导致可以同时运行更多查询，从而提升了可扩展性。有时候，一种优化技术提升了性能的同时更增加了可扩展性。例如，减少查询的内存使用可能不会很大的提高查询性能，但是通过允许同时运行更多的 Impala 查询或其他类型的作业而不会耗尽内存，从而提升了可扩展性。 Note : 在开始任何性能调整和基准测试之前，请确保你的系统已经按照 Post-Installation Configuration for Impala 中的设置进行配置。 Partitioning . 这一技术基于频繁查询的列上的不同的值，把数据物理拆分开来，允许查询跳过读取表中很大部分的数据 Performance Considerations for Join Queries .