I have it set up where I can save my object information to a SQL database using this block of code:
public boolean add(PizzaOrder aOrder) {
boolean success = false;
PreparedStatement statement;
StringBuilder sqlStr = new StringBuilder();
int rowCount;
if (aOrder != null && dbConnect != null && dbConnect.isConnected()) {
try {
sqlStr.append("INSERT INTO ");
sqlStr.append(ORDER_TABLE);
sqlStr.append(" (firstName, lastName, size, cheese, sausage, ham, total)");
sqlStr.append(" VALUES (?,?,?,?,?,?,?)");
statement = dbConnect.getConnection().prepareStatement(sqlStr.toString(), Statement.RETURN_GENERATED_KEYS);
statement.setString(1, aOrder.getFirstName());
statement.setString(2, aOrder.getLastName());
statement.setString(3, aOrder.getPizzaSize());
statement.setBoolean(4, aOrder.getCheese());
statement.setBoolean(5, aOrder.getSausage());
statement.setBoolean(6, aOrder.getHam());
statement.setDouble(7, aOrder.getTotal());
rowCount = statement.executeUpdate();
if (rowCount == 1) {
ResultSet rs = statement.getGeneratedKeys();
if(rs.next()) {
aOrder.setId(rs.getInt(1));
}
success = true;
}
}
catch (SQLException e) {
String prompt = e.getMessage()
+ " cannot save pizza order information for "
+ aOrder.getFullName();
JOptionPane.showMessageDialog(null, prompt, "SQL Server Error: Insert", JOptionPane.ERROR_MESSAGE);
}
}
else if (aOrder == null) {
throw new NullPointerException("Pizza Order object is null");
}
else {
throw new IllegalStateException("Database is not connected");
}
return success;
}
What I am trying to do is change the total variable with an update to the object on the server. I dont have an error right now popping up but nothing is changing in my objects information. Here is my code with the update block:
public boolean update(PizzaOrder aOrder) {
boolean success = false;
PreparedStatement statement = null;
StringBuilder sqlStr = new StringBuilder();
int rowCount;
if(aOrder != null && dbConnect != null && dbConnect.isConnected()) {
try {
//TODO create the SQL and prepared statements to update an order in the database
rowCount = aOrder.getId();
sqlStr.append("UPDATE ");
sqlStr.append("pizzaorder ");
sqlStr.append("SET firstName = ?, lastName = ?, size = ?, cheese = ?, sausage = ?, ham = ?, total = ? WHERE id = ").append(rowCount);
statement = dbConnect.getConnection().prepareStatement(sqlStr.toString());
statement.setString(1, aOrder.getFirstName());
statement.setString(2, aOrder.getLastName());
statement.setString(3, aOrder.getPizzaSize());
statement.setBoolean(4, aOrder.getCheese());
statement.setBoolean(5, aOrder.getSausage());
statement.setBoolean(6, aOrder.getHam());
statement.setDouble(7, aOrder.getTotal());
rowCount = statement.executeUpdate();
}
catch (SQLException e) {
String prompt = e.getMessage()
+ " cannot update pizza order information for "
+ aOrder.getFullName();
JOptionPane.showMessageDialog(null, prompt, "SQL Server Error: Update", JOptionPane.ERROR_MESSAGE);
}
}
else if (aOrder == null) {
throw new NullPointerException("Pizza Order object is null");
}
else {
throw new IllegalStateException("Database is not connected");
}
return success;
}
I have it set up that just the total variable will be changed by the time the update block of code will be ran. So I was trying to just call all the variables again in the hopes that it would change the total.
I get the same results with this update block of code:
public boolean update(PizzaOrder aOrder) {
boolean success = false;
PreparedStatement statement = null;
StringBuilder sqlStr = new StringBuilder();
int rowCount;
if(aOrder != null && dbConnect != null && dbConnect.isConnected()) {
try {
rowCount = aOrder.getId();
sqlStr.append("UPDATE ");
sqlStr.append("pizzaorder ");
sqlStr.append("SET total = ? WHERE id = ").append(rowCount);
statement = dbConnect.getConnection().prepareStatement(sqlStr.toString());
statement.setDouble(1, aOrder.getTotal());
rowCount = statement.executeUpdate();
}
catch (SQLException e) {
String prompt = e.getMessage()
+ " cannot update pizza order information for "
+ aOrder.getFullName();
JOptionPane.showMessageDialog(null, prompt, "SQL Server Error: Update", JOptionPane.ERROR_MESSAGE);
}
}
else if (aOrder == null) {
throw new NullPointerException("Pizza Order object is null");
}
else {
throw new IllegalStateException("Database is not connected");
}
return success;
}
I figured out my problem I had something elsewhere in my code blocking the update. This is the code that is working to update the mySQL database in this case:
try {
//TODO create the SQL and prepared statements to update an order in the database
sqlStr.append("UPDATE ");
sqlStr.append("pizzaorder ");
sqlStr.append("SET total = ? WHERE id = ?");
statement = dbConnect.getConnection().prepareStatement(sqlStr.toString());
statement.setDouble(1, aOrder.getTotal());
statement.setInt(2, aOrder.getId());
rowCount = statement.executeUpdate();
}
Related
Note:
I have two columns (Name(primary key), Email(primary key))
I have inserted two rows.
The 1st row, where name=ema email=ema#gmail.com, and my 2nd row where name=ena email=fe.
Now, when I want to insert a new record it only checks with the 1st row and the checking works, but if I want to insert name=ena and email=something it does not check for the second row. Can someone please suggest to me how do I overcome this?
try
{
Connection connection=DriverManager.getConnection("jdbc:mysql://localhost:3306/testing","root","");
//block of code to check user exists or not.
//Statement statement = connection.createStatement();
PreparedStatement Pstatement;
String query = "select Name,Email from detail";
PreparedStatement ps = connection.prepareStatement(query);
ResultSet rs = ps.executeQuery() ;
if(rs.next())
{
//from database
String name_db1 = rs.getString("Name").trim(); //using trim removes all white spaces
String email_db2 = rs.getString("Email").trim();
//from user GUI
String entered_name = name.getText().trim(); //using trim removes all white spaces
String entered_email = email.getText().trim();
boolean valid = true;
if(entered_name.equals(""))
{
JOptionPane.showMessageDialog(null,"Enter name");
valid = false;
}
else if(name_db1.equals(entered_name))
{
JOptionPane.showMessageDialog(null,"Enter name taken");
name.setText(null);
valid = false;
}
else if(entered_email.equals(""))
{
JOptionPane.showMessageDialog(null,"Enter email");
valid = false;
}
else if(email_db2.equals(entered_email))
{
JOptionPane.showMessageDialog(null,"email taken");
email.setText(null);
valid = false;
}
else if(valid == true)
{
Pstatement=connection.prepareStatement("insert into detail values(?,?)");
//Specifying the values of preparestatement parameter
Pstatement.setString(1,name.getText());
Pstatement.setString(2,email.getText());
Pstatement.executeUpdate();
JOptionPane.showMessageDialog(null,"registration successful");
//x++;
}
}
else
{
//incase if the user click without filling up the fields
JOptionPane.showMessageDialog(null,"not yet registered");
}
}
catch(SQLException e)
{
e.printStackTrace();
}
Finally, I have figured out the logic, I just need to create a separate query for both Name and Email. This way I can search more than two values :D. If there is any mistake please let me know.
try
{
Class.forName("com.mysql.jdbc.Driver");
Connection con = (Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/testing","root","");
//creating a query for Name
String query1 = "select Name, Email from detail where Name like '"+name.getText()+"'";
PreparedStatement statement1 = con.prepareStatement(query1);
//creating a query for Email
String query2 = "select Name, Email from detail where Email like '"+email.getText()+"'";
PreparedStatement statement2 = con.prepareStatement(query2);
ResultSet result1 = statement1.executeQuery(); //resultset for name
ResultSet result2 = statement2.executeQuery(); //resultset for email
//checking name exception
if (result1.next())
{
String dbasename=result1.getString("Name").toString().trim();
String enteredname=new String(name.getText().trim());
if(enteredname.equals(""))
{
JOptionPane.showMessageDialog(null, "enter name");//valid1 = false;
}
else if(dbasename.equals(enteredname))
{
JOptionPane.showMessageDialog(null, "name taken");//valid1 = false;
name.setText(null);
}
}
//checking email exception
else if(result2.next())
{
String dbaseemail=result2.getString("Email").toString().trim();
String enteredemail=new String(email.getText().trim());
if(enteredemail.equals(""))
{
JOptionPane.showMessageDialog(null, "enter email");//valid1 = false;
}
else if(dbaseemail.equals(enteredemail))
{
JOptionPane.showMessageDialog(null, "email taken");//valid1 = false;
email.setText(null);
}
}
//if no exception is detect exectute the below statement
else
{
PreparedStatement Pstatement=con.prepareStatement("insert into detail values(?,?)");
Pstatement.setString(1,name.getText());
Pstatement.setString(2,email.getText());
Pstatement.executeUpdate();
JOptionPane.showMessageDialog(null,"Registered Successfully");
}
statement1.close();
statement2.close();
con.close();
}
catch(SQLException se){
se.printStackTrace();
}
catch(Exception e)
{
e.printStackTrace();
JOptionPane.showMessageDialog(null, "error during searching");
}
I'm trying to send an increase count variable of a picture (which is increased by just increasing +1 everytime a new session hits a picture). I'm getting the following error message however, i'm checking for an empty result set. My thought process is that I can try to select the picturesNo that has been called and if it can't find that pictureNo we simply insert the first count to the table, and if it can find it, we then update this.
Error message:
"SQLException: Illegal operation on empty result set."
Code to increase the count for the session
HttpSession session = request.getSession() ;
Integer counter = (Integer) session.getAttribute("counter");
String accCount = (String) session.getAttribute("attributeKey") ;
String url = "http://localhost:8080/techfore";
String encodedURL = url + ";jsessionid=" + request.getSession().getId();
if (accCount == null || encodedURL == null) { // New session?
response.sendRedirect("/techfore/WelcomePage");
}
else{
if(counter == 0) {
counter = new Integer(counter.intValue() + 1);
session.setAttribute("counter", counter);
}
}
Utilities.initalCount(out, pictureName, counter);
Code to run the queries
public static void initalCount(PrintWriter out, String pictureName, int accessCount) {
Connection con = null;
try { // Connect to the database
con = openConnection(out);
}
catch (Exception e) { // Failed to open the connection
out.println("<P>" + e.getMessage());
}
try {
Statement stmt = con.createStatement();
String query0;
ResultSet rs1;
query0="SELECT PictureNo FROM Statistics WHERE PictureNo = (SELECT PictureNo FROM Pictures WHERE ShortName = '"+pictureName+"')";
rs1 = stmt.executeQuery(query0);
if(rs1.next()){
//yes exist
String description = rs1.getString("Description");
int pictureNo = rs1.getInt("PictureNo");
IncreaseCount(out, pictureNo, accessCount);
}
else {
//if rs is null insert
int pictureNo = rs1.getInt("PictureNo");
AddCount(out, pictureNo, accessCount);
}
stmt.close() ;
}
catch(SQLException ex) {
out.println("<P>SQLException: " + ex.getMessage()) ;
}
}
public static void AddCount(PrintWriter out, int pictureNo, int accessCount) {
Connection con = null;
try { // Connect to the database
con = openConnection(out);
}
catch (Exception e) { // Failed to open the connection
out.println("<P>" + e.getMessage());
return;
}
try {
Statement stmt = con.createStatement();
String query;
ResultSet rs1;
query="INSERT INTO Statistics VALUES "+pictureNo+","+accessCount+" ";
stmt.executeUpdate(query);
stmt.close() ;
}
catch(SQLException ex) {
out.println("<P>SQLException: " + ex.getMessage()) ;
}
}
public static void IncreaseCount(PrintWriter out, int pictureNo, int accessCount) {
Connection con = null;
try { // Connect to the database
con = openConnection(out);
}
catch (Exception e) { // Failed to open the connection
out.println("<P>" + e.getMessage());
return;
}
try {
Statement stmt = con.createStatement();
String query;
ResultSet rs1;
query="UPDATE Statistics SET AccessCount = "+accessCount+" + 1 WHERE PictureNo = "+pictureNo+"";
stmt.executeUpdate(query);
stmt.close() ;
}
catch(SQLException ex) {
out.println("<P>SQLException: " + ex.getMessage()) ;
}
}
New insert
query="INSERT INTO Statistics VALUES (SELECT PictureNo FROM Pictures WHERE FileName = '"+pictureName+"'),"+accessCount+" ";
I am tring to check whether a data is available or not in database table.if not it will insert the data. But in first button click it works perfectly. by when i try to click the button again with the same value it gets inserted into the table. please help someone
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
try {
// TODO add your handling code here:
DefaultTableModel model = (DefaultTableModel) jTable1.getModel();
ArrayList<String> list = new ArrayList<>();
Object obj[] = null;
Class.forName("com.mysql.jdbc.Driver");
java.sql.Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/cem?useSSL=false", "root", "123");
//here stu is database name, root is username and password
Statement stmt = con.createStatement();
String pn = "select gname from games where gname='" + jTextField1.getText() + "'";
ResultSet rsPn = stmt.executeQuery(pn);
System.out.println(rsPn.next());
if (rsPn.next() == false) {
String q = ("insert into games(gid,gname) values(NULL,'" + jTextField1.getText() + "')");
int i = 0;
i = stmt.executeUpdate(q);
if (i > 0) {
System.out.println("success");
list.add(jTextField1.getText());
obj = list.toArray();
model.addRow(obj);
} else {
System.out.println("stuck somewhere");
}
StudentDetails.details();
jTextField1.setForeground(Color.BLACK);
stmt.close();
con.close();
} else {
jTextField1.setForeground(Color.red);
System.out.println("Name Already exist");
}
} catch (SQLException ex) {
Logger.getLogger(InsertPanel.class.getName()).log(Level.SEVERE, null, ex);
} catch (ClassNotFoundException ex) {
Logger.getLogger(InsertPanel.class.getName()).log(Level.SEVERE, null, ex);
}
}
You're calling next() twice:
System.out.println(rsPn.next());
if (rsPn.next() == false) {
The second call will return false even if there's a row already (though it should work once there are two or more rows). Use a variable instead:
boolean hasNext = rdPn.next();
System.out.println(hasNext);
if (!hasNext) {
Hi i am new to programming , i have recently stumbled across this logic error which i couldn't solve. When i click update in the UI , console display success is false.May i know how can i increment executeUpdate to 1?. Thanks in advance
public static boolean updateStaff(Staff staff) {
boolean success = false;
DBController db = new DBController();
String dbQuery;
PreparedStatement pstmt;
//step 1 - establish connection to database
db.getConnection();
//step 2 - declare the SQL statement
dbQuery = "UPDATE staff SET staffID = ?, staffName = ?, staffPassword= ?, staffNRIC = ?, staffGender = ?, staffContactNo = ?, staffEmail = ?, dob = ?, department = ? WHERE id = ?";
pstmt = db.getPreparedStatement(dbQuery);
//step 3 - to update record using executeUpdate method
try {
pstmt.setString(1, staff.getStaffID());
pstmt.setString(2, staff.getStaffName());
pstmt.setString(3, staff.getStaffPassword());
pstmt.setString(4, staff.getStaffNRIC());
pstmt.setString(5, staff.getStaffGender());
pstmt.setInt(6, staff.getStaffContactNo());
pstmt.setString(7, staff.getStaffEmail());
pstmt.setString(8, staff.getDOB());
pstmt.setString(9, staff.getDepartment());
pstmt.setInt(10,staff.getId());
if (pstmt.executeUpdate() == 1)
success = true;
System.out.println("success" + success);
pstmt.close();
} catch (Exception e) {
e.printStackTrace();
}
System.out.println(success);
//step 4 - close connection
db.terminate();
return success;
}
below is the UI
private void actionPerformedUpdate(){
int contact = 0;
if (validateInput()) {
contact = Integer.parseInt(txtStaffContact.getText());
// create an object of expenses based on the input values
Staff e1 = new Staff(txtStaffID.getText(), txtStaffName.getText(),txtStaffNRIC.getText(), txtStaffGender.getText(), contact , txtStaffEmail.getText() , txtStaffDOB.getText() , txtStaffDepartment.getText(),txtStaffPassword.getText());
// insert to database and check return value
if (StaffDA.updateStaff(e1) == true) {
//if(StaffController.createStaff(e1)){
JOptionPane.showMessageDialog(HMSFrame,
"Record created successfully", "Alert",
JOptionPane.INFORMATION_MESSAGE);
// reset text field for next record.
} else if(StaffDA.updateStaff(e1) == false){
JOptionPane.showMessageDialog(HMSFrame,
"Database Error. Record not created.", "Alert",
JOptionPane.ERROR_MESSAGE);
}
}
}
private boolean validateInput() {
boolean result = false;
String msg = "";
int msgType = JOptionPane.ERROR_MESSAGE;
// retrieve the user input from the text box/area provided
String staffID = txtStaffID.getText();
String staffName = txtStaffName.getText();
String staffNRIC = txtStaffNRIC.getText();
String staffGender = txtStaffGender.getText();
String StaffContactNo = txtStaffContact.getText();
String staffEmail = txtStaffEmail.getText();
String dob = txtStaffDOB.getText();
String department = txtStaffDepartment.getText();
if (staffName.length() == 0)
msg += "Please enter staff''s Full Name.\n";
try {
Integer.parseInt(StaffContactNo); // convert to Integer for time
} catch (NumberFormatException e) {
if (StaffContactNo.length() > 8)
msg += "Plese enter hours in 24 hour clock format.\n";
}
if (msg.length() == 0)
result = true;
else
JOptionPane.showMessageDialog(HMSFrame, msg, "Alert", msgType);
return result;
}
I am writing a program that will take in a student ID and verify if that ID exists in a mysql table. If it does exist, I would like to take the entire row that it exists in and copy that row to another table. Currently the program will just copy all rows in a table to the other. Any help appreciated. I have inserted a snippet of code below.
try {
String compareText = IDField.getText().trim();
if(compareText.length() > 0){
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/simlab","root","password");
System.out.println("Connected to database");
Statement stmt1 = conn.createStatement();
ResultSet rs1 = stmt1.executeQuery("select * from students where LUID='"+IDField.getText()+"' ");
boolean isPresent = rs1.next();
if (isPresent)
{
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/simlab","root","password");
System.out.println("Connected to database");
int rows = stmt1.executeUpdate("INSERT INTO skills(ID_Student,LUID_Student)SELECT ID, LUID FROM students");
if (rows == 0)
{
System.out.println("Don't add any row!");
}
else
{
System.out.println(rows + " row(s)affected.");
conn.close();
}
//System.out.println("Already exists!!");
}
You could all do that in a single SQL statement:
INSERT INTO <Dest-Table>
(SELECT * FROM <Src-Table> WHERE ID=?);
It will only copy rows that exist.
I suspect it's due to this line:
int rows = stmt1.executeUpdate("INSERT INTO skills(ID_Student,LUID_Student)SELECT ID, LUID FROM students");
As, if that line is parsed, the SELECT statement has no WHERE clause, and will therefore get every row, and therefore insert everything.
With Prepared statements
String sql = "INSERT INTO abc"
+ "(SELECT id1,id2 FROM pqr)";
ps1 = con.prepareStatement(sql);
int rs = ps1.executeUpdate();
if (rs > 0) {
update = true;
} else {
update = false;
}
} catch (Exception ex) {
ex.printStackTrace();
} finally {
try {
if (ps1 != null) {
ps1.close();
ps1 = null;
}
if (con != null) {
con.close();
con = null;
}
} catch (Exception e) {
}
}
return update;