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Unable to cast object of type 'System.DBNull' to type 'System.String`

... There are several scenarios where you might prefer convert to an explicit cast. @romanm noted one of them. Another one is when you work with decimals and care about the different rounding mechanisms that Convert.ToInt32 and (int) use. The former rounds to the nearest even value, while the explicit ...
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How can I group by date time column without taking time into consideration

... Cast/Convert the values to a Date type for your group by. GROUP BY CAST(myDateTime AS DATE) share | improve this answer ...
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Access to the path is denied

...ption message is not ideal, but it comes straight from the OS and they are cast in stone. The framework often adds extra checks to generate better messages, but this is an expensive test on a network. Perf is a feature too. You need to use a name like 'C:\inetpub\wwwroot\mysite\images\savehere\m...
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How do I convert a string to a number in PHP?

...mstances. For situations where you do want to explicitly convert the type, cast it: $num = "3.14"; $int = (int)$num; $float = (float)$num; share | improve this answer | fol...
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Regular expression for a hexadecimal number?

... @NiklasB. Your shorthand is only valid if using perl regex, if using POSIX regex, then Steven's solution is the shortest. Either way, Steven's solution works for both perl and POSIX regex. – David M. Syzdek ...
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What's the best way to put a c-struct in an NSArray?

...tableArray *)arrayRef; struct {int member;} myStruct = {.member = 42}; // Casting to "id" to avoid compiler warning [array addObject:(id)&myStruct]; // Hurray! struct {int member;} *mySameStruct = [array objectAtIndex:0]; The above example completely ignores the issues with respect to memory...
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How can I convert a long to int in Java?

...ted, in Java 8: Math.toIntExact(value); Original Answer: Simple type casting should do it: long l = 100000; int i = (int) l; Note, however, that large numbers (usually larger than 2147483647 and smaller than -2147483648) will lose some of the bits and would be represented incorrectly. For ...
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How do I make the method return type generic?

...nimal> T callFriend(String name, Class<T> type) { return type.cast(friends.get(name)); } Then call it as such: jerry.callFriend("spike", Dog.class).bark(); jerry.callFriend("quacker", Duck.class).quack(); This code has the benefit of not generating any compiler warnings. Of course ...
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Generate a random alphanumeric string in Cocoa

... oh the compiler would give a warning for losing precision, so better to cast to int arc4random_uniform((int)[letters length]) – knshn Jun 12 '14 at 9:58 ...
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How can I convert a std::string to int?

...stinguish between bad input (see here). 4. Fourth option: Boost's lexical_cast #include <boost/lexical_cast.hpp> #include <string> std::string str; try { int i = boost::lexical_cast<int>( str.c_str()); float f = boost::lexical_cas...