parent-child

recursive self query

由 Deadly 提交于 2019-11-26 16:09:56
问题 I have the following table: myTable: +----+----------+ | id | parentID | +----+----------+ | 1 | null | | 2 | 1 | | 3 | 1 | | 4 | 2 | | 5 | 4 | ----------------- i would like to get all rows tracing back until there's no parentID anymore. So ".... WHERE id=5" would give me: 5, 4, 2, 1 回答1: You are organizing your hierarchical data using the adjacency list model. The fact that such recursive operations are difficult is in fact one major drawback of this model. Some DBMSes, such as SQL Server

Order navigation properties when using Include and/or Select methods with EF 4.1 Code-First?

由 北战南征 提交于 2019-11-26 08:19:33
问题 This is the second step of a question explained here: EF 4.1 code-first: How to load related data (parent-child-grandchild)?. With @Slauma\'s guidance, I have successfully retrieved data with this approach: var model = DbContext.SitePages .Where(p => p.ParentId == null && p.Level == 1) .OrderBy(p => p.Order) // ordering parent .ToList(); foreach (var child in model) { // loading children DbContext.Entry(child) .Collection(t => t.Children) .Query() .OrderBy(t => t.Order) // ordering children

Are child processes created with fork() automatically killed when the parent is killed?

由 空扰寡人 提交于 2019-11-26 08:08:16
问题 I\'m creating child processes with fork() in C/C++. When the parent process ends (or is killed for some reason) I want all child processes to be killed as well. Is that done automatically by the system? Or I have to do it myself? Thanks. Pre-existing similar questions: How can I cause a child process to exit when the parent does? How to make child process die after parent exits? 回答1: No. If the parent is killed, children become children of the init process (that has the process id 1 and is

Style <select> element based on selected <option>

由 天涯浪子 提交于 2019-11-26 06:42:21
问题 Is it possible to style a select element based on what option is selected with CSS only? I am aware of existing JavaScript solutions. I tried to style the option element itself, but this will give style only to the option element in the list of options, not to the selected element. select[name=\"qa_contact\"] option[value=\"3\"] { background: orange; } http://jsfiddle.net/Aprillion/xSbhQ/ If not possible with CSS 3, will CSS 4 subject selector help in the future - or will this stay a

JavaScript DOM: Find Element Index In Container

由 邮差的信 提交于 2019-11-26 06:28:58
问题 I need to find an index of element inside its container by object reference. Strangely, I cannot find an easy way. No jQuery please - only DOM. UL LI LI LI - my index is 2 LI Yes, I could assign IDs to each element and loop through all nodes to match the ID but it seems a bad solution. Isn\'t there something nicer? So, say I have an object reference to the third LI as in the example above. How do I know it is index 2? Thanks. 回答1: You could make usage of Array.prototype.indexOf . For that, we

How to set opacity in parent div and not affect in child div? [duplicate]

由 巧了我就是萌 提交于 2019-11-26 01:59:19
问题 This question already has an answer here: I do not want to inherit the child opacity from the parent in CSS 14 answers Hey i am searching in google but i can\'t fine any perfect answer I want to Opacity in parent DIV but not Child DIV Example HTML <div class=\"parent\"> <div class=\"child\"> Hello I am child </div> </div> Css .parent{ background:url(\'../images/madu.jpg\') no-repeat 0 0; } .child{ Color:black; } Note: -- I want to background-image in Parent Div not Color 回答1: May be it's good

How to pass data from 2nd activity to 1st activity when pressed back? - android

由 前提是你 提交于 2019-11-26 01:35:07
问题 I\'ve 2 activities, Activity1 and Activity2 . In Activity1 I\'ve a Button and TextView . When the button is clicked Activity2 is started. In Activity2 I\'ve an EditText . I want to display the data retrieved from EditText in Activity2 in the TextView in Activity1 when back is pressed from Activity2 . can someone help me with the code to make this work? 回答1: Start Activity2 with startActivityForResult and use setResult method for sending data back from Activity2 to Activity1. In Activity1 you

How do I pass a value from a child back to the parent form?

由 纵饮孤独 提交于 2019-11-26 01:31:48
How do I pass a value from a child back to the parent form? I have a string that I would like to pass back to the parent. I launched the child using: FormOptions formOptions = new FormOptions(); formOptions.ShowDialog(); Create a property (or method) on FormOptions , say GetMyResult : using (FormOptions formOptions = new FormOptions()) { formOptions.ShowDialog(); string result = formOptions.GetMyResult; // do what ever with result... } If you're just using formOptions to pick a single value and then close, Mitch's suggestion is a good way to go . My example here would be used if you needed the

How do I pass a value from a child back to the parent form?

由 安稳与你 提交于 2019-11-26 01:07:50
问题 How do I pass a value from a child back to the parent form? I have a string that I would like to pass back to the parent. I launched the child using: FormOptions formOptions = new FormOptions(); formOptions.ShowDialog(); 回答1: Create a property (or method) on FormOptions , say GetMyResult : using (FormOptions formOptions = new FormOptions()) { formOptions.ShowDialog(); string result = formOptions.GetMyResult; // do what ever with result... } 回答2: If you're just using formOptions to pick a

Make absolute positioned div expand parent div height

由 本小妞迷上赌 提交于 2019-11-26 00:59:35
问题 As you can see in the CSS below, I want child2 to position itself before child1 . This is because the site I\'m currently developing should also work on mobile devices, on which the child2 should be at the bottom, as it contains the navigation which I want below the content on the mobile devices. - Why not 2 masterpages? This is the only 2 divs which are repositioned in the entire HTML, so 2 masterpages for this minor change is an overkill. HTML: <div id=\"parent\"> <div class=\"child1\"><
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