Web Forms :: Inserting Multiple Rows In A Single SQL Query

I have a question which is insert multiple rows in a single insert? Is that possible?

For example:

INSERT INTO EMPLOYEE(NAME, AGE)
VALUES
(JAN, 18),
(JEN, 20),
(JIN, 23)
Using C#

I have code, something like I ask but there's an error.

Here's the code

string sql = "INSERT INTO EMPLOYEE(NAME, AGE) VALUES";
for(int i = 0; i < data.length; i++)
{
sql += "(@name" + i.ToString() ", @age" + i.ToString() + "),"
}
sql = sql.Remove(sql.Length - 1);
cmd = SqlCommand(sql, con);
cmd.ExecuteNonQuery;

I got an error of "Fatal error encountered during command execution."

The error goes here

{"Parameter '@name0' must be defined."}