Introduction

You can create a default value of a column when creating a table. To specify the default value of a column, in the top section, click the column. In the bottom section, click Default Value or Binding, type the desired value following the rules of the column's data type:

It the Data Type is	Intructions
Text-based (char, varchar, text, and their variants)	Enter the value in single-quotes
Numeric-based	Enter the value as a number but following the rules of the data type. For example, if you enter a value higher than 255 for a tinyint, you would receive an error
Date or Time	Enter the date as either MM/DD/YYYY or YYYY/MM/DD. You can optionally include the date in single-quotes. Enter the time following the rules set in the Control Panel (Regional Settings).
Bit	Enter the value as 0 for FALSE or any other long integer value for TRUE

To specify the default value in a SQL statement, when creating the column, before the semi-colon or the closing parenthesis of the last column, assign the desired value to the DEFAULT keyword. Here are examples:

private void btnDatabase_Click(object sender, EventArgs e)
{
    using (SqlConnection connection =
	new SqlConnection("Data Source=(local);" +
			  "Database='Exercise1';" +
			  "Integrated Security=yes;"))
    {
	SqlCommand command =
	    new SqlCommand("CREATE TABLE Employees " +
			   "( " +
			   "FullName VARCHAR(50), " +
			   "Address VARCHAR(80), " +
			   "City VARCHAR(40), " +
			   "State VARCHAR(40) DEFAULT = 'NSW', " +
			   "PostalCode VARCHAR(4) DEFAULT = '2000', " +
			   "Country VARCHAR(20) DEFAULT = 'Australia');",
			   connection);
	connection.Open();
	command.ExecuteNonQuery();

	MessageBox.Show("A new table named Employees has been created");
    }
}

After creating the table, the user does not have to provide a value for a column that has a default. If the user does not provide the value, the default would be used when the record is saved.

If the user provides a value for a column that has a default value and then deletes the value, the default value rule would not apply anymore: The field would simply become empty