compare

So here is my issue I am comparing new and old values when a table row is being updated. But the new or old value will sometimes be null. So the code below doesn't work. Can can I remedy this issue? Thank You BEFORE UPDATE ON mytable FOR EACH ROW BEGIN IF OLD.assignedto != NEW.assignedto THEN INSERT INTO history ( asset , changedfield , oldvalue , newvalue ) VALUES ( NEW.asset, 'assignedto', OLD.assignedto, NEW.assignedto ); END IF; END$$ Try: IF ( (OLD.assignedto IS NOT NULL AND NEW.assignedto IS NOT NULL AND OLD.assignedto != NEW.assignedto) OR (OLD.assignedto IS NULL AND NEW.assignedto IS

I am confused about the interface of std::find . Why doesn't it take a Compare object that tells it how to compare two objects? If I could pass a Compare object I could make the following code work, where I would like to compare by value, instead of just comparing the pointer values directly: typedef std::vector<std::string*> Vec; Vec vec; std::string* s1 = new std::string("foo"); std::string* s2 = new std::string("foo"); vec.push_back(s1); Vec::const_iterator found = std::find(vec.begin(), vec.end(), s2); // not found, obviously, because I can't tell it to compare by value delete s1; delete

How can I compare two Version number strings? For example: 3.1.1 and 3.1.2.5.4 Now I need to find out if 3.1.2.5.4 is higher than 3.1.1 but I don't know how to do this. Can anybody help me? Thanks in advance! Sample Code : NSString* v1 = @"3.1.1"; NSString* v2 = @"3.1.2.5.4"; if ([v1 compare:v2 options:NSNumericSearch] == NSOrderedDescending) { NSLog(@"%@ is greater than %@",v1,v2); } From the Apple Documentation for Comparing and sorting strings . Paras Yes, you can compare the versions, please refer the code below: public class Comparision { string ver1, ver2; public static void main(String

1.盡量用基本類型，原因是null == int的情況，性能問題，比較問題3個問題 Comparator<Integer> order = (i, j) -> (i < j) ? -1 : ((i == j) ? 0 : 1); int compare = order.compare(new Integer(2), new Integer(2) ); System.out.println(compare); 這裏輸出的預期應該是0，但實際是1。分析過程，i < j 這邊就自動拆箱成nt，然後i == j，==這裏是對象引用判斷，所以為假，則得出0了。 改成下面這種就可以了。 Comparator<Integer> order = (i, j) -> { int a = i, b = j; return i < j ? -1 : (i == j ? 0 : 1); }; 還有要注意下面這種錯誤的代碼，它會出null指針異常，編譯不過。因爲Integer會功能值有null，所以存在null == int這種情況，所以應該改爲int定義i。 static Integer i; public static void main(String[] args) { if (i == 2) { System.out.println("ok"); } } 那么，什么时候应该使用包装类型呢

Short version When I compare two forks on Github, it does not compare the latest states, but the current state of the base fork with the last common commit (or am I wrong?); so how can I compare the latest states/heads on Github? Longer version I am trying to compare two repositories on Github. It does not seem to compare the latest states of both repository. Instead, it compares: the base fork as it was when both repositories where identical (last common commit?) with the head fork as it is now. You can see this in the Github's fork comparison example , it says there are no changes between

I wish to know if a string contains one of abc , def , xyz , etc. I could do it like: $a.Contains("abc") -or $a.Contains("def") -or $a.Contains("xyz") Well it works, but I have to change code if this substring list changes, and the performance is poor because $a is scanned multiple times. Is there a more efficient way to do this with just one function call? You could use the -match method and create the regex automatically using string.join: $referenz = @('abc', 'def', 'xyz') $referenzRegex = [string]::Join('|', $referenz) # create the regex Usage: "any string containing abc" -match

作为一款实用的文件和文件夹比较工具，Beyond Compare软件操作简单，功能全面。为了帮助用户更好的执行比较会话操作。每一个比较会话界面都设置了独一无二的工具栏，其中工具栏提供各种编辑工具，为方便使用以提高效率，一般都在操作界面的相应位置上设立各种工具图标，确保可以方便快捷地进行比较操作。可能有的用户在进行比较会话时想要隐藏 Beyond Compare 工具栏，接下来就和大家简单讲解一下隐藏工具栏的方法。 具体操作步骤如下 由于Beyond Compare可执行的比较会话类型丰富，包括：文件夹比较、合并和同步，文本比较，表格比较，图片比较等，本文主要以图片比较会话为例，进行隐藏工具栏的简述。 步骤一：打开Beyond Compare软件，在主页面左侧新建会话栏目下选择“图片比较”会话，打开会话操作界面，分别单击界面左右两侧“打开文件“按钮，选择需要比较的图片文件，如下图图例所示，工具栏默认以“图标和文本”的形式显示。 Beyond Compare图片比较会话操作界面图例 步骤二：您可以右键单击任一工具栏栏目中的操作图标，并在展开的菜单中选择“隐藏工具栏“命令，其中展开菜单的内容还包括：以图标和文本显示工具栏、仅以图标显示工具栏、工具栏选项。 Beyond Compare右键单击工具栏图标展开菜单图例 步骤三：执行完“隐藏工具栏”的命令后，再次回到图片比较会话操作界面