Automatic Numbering for the Primary Key Column
You can designate a column in your table as an auto-increment column. This
column will be automatically populated with a number that will be the primary
key.
To set up an auto-increment column follow these
steps
- Set the AutoIncrement property of your data column to true.
- Set the AutoIncrementSeed property to the value of
the first number you want.
- Set the AutoIncrementStep property to the value you want to increment by each time a new row is added.
Following code sample shows how to create an Autoincrementing
Primary Key
using System;
using System.Data;
namespace AutoIncrement
{
class Program
{
static void Main(string[]
args)
{
// Create
a table and add two columns Id and Name
DataTable
objmyTable = new DataTable();
DataColumn
objColumn = objmyTable.Columns.Add("Id",
typeof(int));
objmyTable.Columns.Add("Name", typeof(string));
// Make
the Id column the primary key
objmyTable.PrimaryKey = new DataColumn[] {
objmyTable.Columns["Id"] };
// Set
AutoIncrement property of column to true
objColumn.AutoIncrement = true;
// set
autoincremented column starting at 25
objColumn.AutoIncrementSeed = 25;
// and
incrementing by 25 with each new record added
objColumn.AutoIncrementStep = 25;
// Add
rows to table
objmyTable.Rows.Add(new object[]{ null,"mukesh"});
objmyTable.Rows.Add(new object[]{null, "vinay"});
objmyTable.Rows.Add(new object[]{null, "ashish"});
Console.WriteLine("Id \tName");
Console.WriteLine("-------------");
foreach
(DataRow row in
objmyTable.Rows)
Console.WriteLine("{0}\t{1}", row["Id"],
row["Name"]);
Console.WriteLine("\nPress any key to continue.");
Console.ReadLine();
}
}
}
Output :