DECLARE @MyValue int SELECT @MyValue = Column1 WHERE Column2 > 50 IF @MyValue IS NULL BEGIN RAISEERROR(‘This is my custom message from SQL.’, 16, 1) END ELSE SELECT MyValue END Use an error code within 11-16, or just use 16 for a “general” case. RAISERROR(‘This is my custom message from SQL.’,16,1) Why? Here’s summary of […]
The IndexOf() method returns the index number of the first matched character whereas the LastIndexOf() method returns the index number of the last matched character. using System; public class StringExample { public static void Main(string[] args) { string s1 = “Hello C#”; int first = s1.IndexOf(‘l’); int last = s1.LastIndexOf(‘l’); Console.WriteLine(first); Console.WriteLine(last); } } Output: […]
DateTime myDate; if(DateTime.TryParse(txtBirthDate.Text, out myDate)) { //Valid Date } else { //Invalid Date }
string myList = “9,3,12,43,2”; List<int> intList = myList.Split(‘,’).Select(int.Parse).ToList();
List<int> list = new List<int>() {1,2,3}; string.Join<int>(“,”, list) Join has generic overloads. It is so much easier to use it in that way to convert your list to the different types.
string sNumbers = “1,2,3,4,5”; var numbers = sNumbers.Split(‘,’).Select(Int32.Parse).ToList();
new[] {“,”, “/”}.Any(input.Contains) or you can use Regex Regex.IsMatch(input, @”[,/]”);
Table below shows the default value for the different predefined data types. Type Default sbyte, byte, short, ushort, int, uint, long, ulong 0 char ‘\x0000’ float 0.0f double 0.0d decimal 0.0m bool false object null string null As you can see, for the integral value types, the default value is zero. The default value for […]
string myValueToSplit = “Istanbul, Tokyo, Seoul, Bangkok, Bali, Minsk, Belgrade, Kiev”; var theFirstValue = myValueToSplit.Split(‘,’)[0]; //OUTPUT: theFirstValue = “Istanbul” //You can change [0] as you wish. //For example, if you want to get Kiev, make it [7]
Constructor is a special method of the class that is automatically invoked when an instance of the class is created is called a constructor. The main use of constructors is to initialize the private fields of the class while creating an instance for the class. When you have not created a constructor in the class, the compiler […]
In C# (and many other languages) you will find that you use new often as it is fundamental to using types and classes. The new keyword does pretty much what it says: it will create a new instance of a class or type, assigning it a location in memory. Let me try and illustrate this. Company company; Here […]
To calculate the sum of a column in a DataTable use the DataTable.Compute method. DataTable dt; … int sumValue; sumValue = dt.Compute(“Sum(TheSumColumn)”, string.Empty);
Sometimes you want to run your code only when it is not in debug mode. You can use #IF DEBUG code block for this purpose #if DEBUG LogMail(“It is in debug mode, only add a log record.”) #else SendMail(“It is not in debug mode, so you can send e-mail.”) #endif
dataTable.DefaultView.ToTable(true, “target_column”); first parameter in ToTable() is a boolean which indicates whether you want distinct rows or not. second parameter in the ToTable() is the column name based on which we have to select distinct rows. Only these columns will be in the returned datatable. If you need to get distinct based on two columns: dataTable.DefaultView.ToTable(boolean, params string[] columnNames)