Filter with LINQ DataTable C#

C# > System.Data   > DataTable > Filter with LINQ

Example:

DataTable dt = new DataTable("table");

dt.Columns.Add("id", Type.GetType("System.Int32"));

dt.Columns.Add("name", Type.GetType("System.String"));

DataRow dr = dt.NewRow();

dr["id"] = 1;

dr["name"] = "john";

dt.Rows.Add(dr);

dr = dt.NewRow();

dr["id"] = 2;

dr["name"] = "dan";

dt.Rows.Add(dr);

DataTable tbl = (from DataRow dr1 in dt.Rows

                     where dr1["id"].ToString() == "1"

                     select dr).CopyToDataTable();

DateValue Visual Basic Example

VB.NET > Functions > DateValue 

Returns a date value containing the date information represented by a string.

Example

Dim dt As Date

dt = DateValue("March 21, 2014")

MessageBox.Show(dt)

Oracle Sequence Example

Oracle > Sequence

Sequences are database objects from which multiple users can generate unique integers. The sequence generator generates sequential numbers, which can help to generate unique primary keys automatically, and to coordinate keys across multiple rows or tables.

Example:

CREATE SEQUENCE order_sequence

      INCREMENT BY 1

      START WITH 1

      NOMAXVALUE

      NOCYCLE

      CACHE 10;

INSERT INTO orders (order_no)

VALUES (order_sequence.NEXTVAL);

Var C# Example

C# > Types > Var

Var is implicitly typed.

An implicitly typed local variable is strongly typed, but 

the compiler determines the type. 


Example

// var is required because the select clause specifies an anonymous type 

var query = from prod in products

            where prod.Category == "shoes"

            select new { prod.Name, prod.Price };

// var is required because item is an anonymous type

foreach (var item in query)

{

               

}

C# Void Type Example

C# > Types > Void

Void specifies that the method doesn't return a value.

Example

private void Log(string msg)

{

   // log method

}

SQL Server Drop

SQL Server > DDL > Drop

DROP statements removes existing entities.

• DROP TABLE
• DROP TRIGGER

DateDiff Visual Basic Example

VB.NET > Functions > DateDiff

Returns a value specifying the number of time intervals 
between two dates.

Example:

Dim dt1 As Date = #3/1/2014#

Dim dt2 As Date = #4/1/2014#

MessageBox.Show("Day diff: " & DateDiff(DateInterval.Day, dt1, dt2) & " Week diff: " & DateDiff(DateInterval.Weekday, dt1, dt2))