LEFT SQL Server Example

SQL Server > Built-in Functions > LEFT

Returns the left part of a string with the specified number of characters.

Example:

declare @str nvarchar(max)
set @str='SQL Server'
select left(@str,3)

result:
SQL

LEN SQL Server Example

SQL Server > Built-in Functions > LEN

Returns then length of string expression.

Example

declare @str nvarchar(max)

set @str='SQL Server'

select Len(@str)

result:
10

HOST_NAME SQL Server Example

SQL Server > Built-In Functions > HOST_NAME


Represents the workstation name, name of computer connected to SQL Server.

SELECT HOST_NAME()

LINQ DataTable compare date VB.NET

VB.NET > Data > DataTable > Filter with LINQ

LINQ DataTable compare date VB.NET example

   Dim dt As DataTable = New DataTable("table")

        dt.Columns.Add("id", Type.GetType("System.Int32"))
        dt.Columns.Add("name", Type.GetType("System.String"))
        dt.Columns.Add("date_of_birth", Type.GetType("System.DateTime"))
 

        Dim dr As DataRow = dt.NewRow()

        dr("id") = 1
        dr("name") = "john"
        dr("date_of_birth") = #1/1/2000#
        dt.Rows.Add(dr)

        dr = dt.NewRow()

        dr("id") = 2
        dr("name") = "dan"
        dr("date_of_birth") = #9/11/1973#
        dt.Rows.Add(dr)

        Dim filteredTable As DataTable = (From n In dt.AsEnumerable()

                            Where n.Field(Of Date)("date_of_birth") = #9/11/1973#
                    Select n).CopyToDataTable()

DateAdd VB.NET Example

VB.NET > Functions > DateAdd

DateAdd: add or subtract a specified time interval from a date.

Example:

Label1.Text = Date.Now
Label2.Text = DateAdd(DateInterval.Day, 1, Date.Now)
Label3.Text = DateAdd(DateInterval.Month, 1, Date.Now)
Label4.Text = DateAdd(DateInterval.Year, 1, Date.Now)

LINQ FirstOrDefault C# Example

C# > LINQ > FirstOrDefault

Returns the first element of the sequence that satisfies a condition or a default value if no such element is found.

Example

string[] cars = { "audi", "ford", "mercedes", "dacia" };
string car = cars.FirstOrDefault(c => c == "ford"); //ford
car = cars.FirstOrDefault(c => c == "ford1"); //null

          

  

Single LINQ C# Example

C# > LINQ > Single

Returns the only element of a sequence that satisfies a specified condition, and throws an exception if more than one such element exists.

Example

            string[] cars = { "audi", "ford", "mercedes", "dacia" };
            try
            {
                string car = cars.Single(c => c == "ford");
            }
            catch (System.InvalidOperationException)
            {
                MessageBox.Show ("Car not found!");
            }