public bool insertLending(Lending lending)
{
try
{
conn.Open();
OleDbCommand cmd = new OleDbCommand(insertBorrowSQL, conn);
cmd.Parameters.AddWithValue("@isbn", lending.ISBN);
cmd.Parameters.AddWithValue("@borrowtime", GetDateWithoutMilliseconds(DateTime.Now));
cmd.Parameters.AddWithValue("@borrowerid", lending.BorrowerID);
cmd.Parameters.AddWithValue("@borrowername", lending.BorrowerName);
cmd.ExecuteNonQuery();
return(true);
}
catch (OleDbException ex)
{
Console.WriteLine(ex);
}
finally
{
conn.Close();
}
return(false);
}
public int returnBook(Lending lending)
{
try
{
conn.Open();
OleDbCommand cmd = new OleDbCommand(returnBookSQL, conn);
cmd.Parameters.AddWithValue("@returntime", GetDateWithoutMilliseconds(DateTime.Now));
cmd.Parameters.AddWithValue("@isbn", lending.ISBN);
cmd.Parameters.AddWithValue("@borrowername", lending.BorrowerName);
cmd.Parameters.AddWithValue("@borrowerid", lending.BorrowerID);
int rowsAffected = cmd.ExecuteNonQuery();
return(rowsAffected);
}
catch (OleDbException ex)
{
Console.WriteLine(ex);
}
finally
{
conn.Close();
}
return(0);
}
public bool checkStudentBookUnreturnExist(Lending lending)
{
try
{
conn.Open();
OleDbCommand cmd = new OleDbCommand(selectStudentBookUnreturnedCountSQL, conn);
cmd.Parameters.AddWithValue("@isbn", lending.ISBN);
cmd.Parameters.AddWithValue("@borrowername", lending.BorrowerName);
cmd.Parameters.AddWithValue("@borrowerid", lending.BorrowerID);
OleDbDataReader reader = cmd.ExecuteReader();
if (reader.HasRows || reader != null)
{
while (reader.Read())
{
return(true);
}
}
else
{
return(false);
}
}
catch (OleDbException ex)
{
Console.WriteLine(ex);
}
finally
{
conn.Close();
}
return(false);
}
private void continue_btn_Click(object sender, EventArgs e)
{
ArrayList lendingList = new ArrayList();
string[] allTextBoxes = { book1ISBN_textbox.Text, book2ISBN_textbox.Text, book3ISBN_textbox.Text, book4ISBN_textbox.Text };
// book id list for duplicate checking only
List <string> isbnListForDC = new List <string>();
int emptyTextboxCount = 0;
foreach (string ISBN in allTextBoxes)
{
if (!String.IsNullOrEmpty(ISBN))
{
Lending lending = new Lending();
lending.ISBN = ISBN.ToUpper();
lendingList.Add(lending);
isbnListForDC.Add(ISBN.ToUpper());
}
else
{
emptyTextboxCount++;
}
}
if (emptyTextboxCount == allTextBoxes.Count())
{
MessageBox.Show("Please scan a book's barcode.", "Empty Field", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
if (!checkDuplicateBook(isbnListForDC))
{
if (actionType.Equals("Borrow"))
{
MessageBox.Show("You cannot borrow the same book.", "Duplicate Book", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
else if (actionType.Equals("Return"))
{
MessageBox.Show("You are trying to return many same books.", "Duplicate Book", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
}
// check if book id is valid
foreach (Lending lending in lendingList)
{
if (dbManager.isbnExists(lending.ISBN) == false)
{
MessageBox.Show("The book ID " + lending.ISBN + " does not exist, no such book.", "Invalid Book ID", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
}
if (actionType.Equals("Borrow"))
{
foreach (Lending lending in lendingList)
{
int unreturnedQuantity = dbManager.selectUnreturnQuantity(lending.ISBN);
int totalQuantity = dbManager.selectBook(lending.ISBN).Quantity;
bool bookAvailable = totalQuantity > unreturnedQuantity;
if (bookAvailable == false)
{
MessageBox.Show("Please return the book ID " + lending.ISBN + " before trying to borrow.", "Book Not Available", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
}
Action frmAction = new Action(actionType, lendingList);
frmAction.Show();
this.Owner = frmAction;
this.Hide();
}
else if (actionType.Equals("Return")) //return book
{
Action frmAction = new Action(actionType, lendingList);
frmAction.Show();
this.Owner = frmAction;
this.Hide();
}
}
