Debug.Assert((theData.Length % 3) == 0); // 'theData' will always be divisible by 3
for (int i = 0; i < theData.Length; i += 3)
{
//grab 3 items at a time and do db insert,
// continue until all items are gone..
string item1 = theData[i+0];
string item2 = theData[i+1];
string item3 = theData[i+2];
// use the items
}