How to show all records in database to JTable? - java

Excuse me. I want to show all records in JTable. But I get confused because my coding just show 1 record. When I click it again, that just show same records.
Can you help me how to get all records?
try {
Statement stmt;
stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM menu");
if (rs.next()) {
String menu_id = rs.getString("menu_id");
String menu_type = rs.getString("menu_type");
String menu_cat = rs.getString("menu_cat");
String menu_name = rs.getString("menu_name");
String menu_price = rs.getString("menu_price");
DefaultTableModel model = (DefaultTableModel) tblMenu.getModel();
model.addRow(new Object[]{menu_id, menu_type, menu_cat, menu_name, menu_price});
}
} catch (Exception e) {
System.out.println("Failed " + e);
}
I have no Idea how to code it. Thank you

Change
if (rs.next())
to
while (rs.next())
to run to the code block not just once, but till the end of the ResultSet.
It should actually look like this
DefaultTableModel model = (DefaultTableModel) tblMenu.getModel();
while (rs.next()) {
String menu_id = rs.getString("menu_id");
String menu_type = rs.getString("menu_type");
String menu_cat = rs.getString("menu_cat");
String menu_name = rs.getString("menu_name");
String menu_price = rs.getString("menu_price");
model.addRow(new Object[]{menu_id, menu_type, menu_cat, menu_name, menu_price});
}

Try this
String[] cols={"id","type","cat","name","price"};
ArrayList<String[]> list = new ArrayList<String[]>();
while (rs.next()) {
String menu_id = rs.getString("menu_id");
String menu_type = rs.getString("menu_type");
String menu_cat = rs.getString("menu_cat");
String menu_name = rs.getString("menu_name");
String menu_price = rs.getString("menu_price");
list.add(new String[]{menu_id, menu_type, menu_cat, menu_name, menu_price});
}
String[][] elts= new String[list.size()][];
elts = list.toArray(elts);
JTable table = new JTable(elts,cols);
JScrollPane pane = new JScrollPane(table, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
frame.getContentPane().add(pane);

You have used if(rs.next()) you know that if condition checked if it is true or false.
rs.next()
shifts the cursor to the next row of the result set from the database and returns true if there is any row, otherwise false. In combination with the if statement (instead of the while) this means that you expecting in only one row. simply,
rs.next()
check for next row if it is exist if condition passed and do the code block and get out from the block run the rest of the code.
As to the concrete question about iterate through the database table and add all to the jTable. You only have to change one keyword,
if to while
What happens when you use while keyword instead if keyword is that rs.next() check for next row and if it is true then condition true for while loop and go through the code block and when block is finish again check for next row. Likewise go through the all rows in your table and condition will fail after last row.

Related

Using PreparedStatement to sort records in MySQL

Im trying to write a code in which when a user will click an a "Sort by Name" button, my program will sort the records of my Database and put them in a JTable,combining 2 DB Tables with INNER JOIN. I have managed to do this by using a resultSet and selecting for example Ascending Order. But because I dont want to have 2 buttons, one for the ASC and one for the DESC, I thought of using preparedStatement and an showInputDialog in which the user will select if he wants to have an ASC or a DESC ordering and execute the order. Also, I remembered that some programs I've seen used a feature in which the first time you clicked the button it sorted DESC and if you pressed it again would order by ASC(havent managed to find in on the WEB).About my first thought, I tried to do it but I could get past this one
ResultSetMetaData mdsort = rssort.getMetaData();
I should have an ResultSet variable(rssort) to use getMetaData() but if I selected to make the program with my PreparedStatement i would get an error there. Any suggestions??
try{
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/test1?user=me&password=12345");
Statement stmtsort = conn.createStatement();
ResultSet rssort = stmtsort.executeQuery("SELECT * FROM consoles INNER JOIN hardware ON consoles.id=hardware.id ORDER BY consoles.name ASC");
// ERROR HERE!!! needs resultset,not preparedStatement
ResultSetMetaData mdsort = rssort.getMetaData();
columnCount = mdsort.getColumnCount();
String[] colssort = new String[columnCount];
for (i=1;i<= columnCount;i++)
{
colssort[i-1] = mdsort.getColumnName(i);
}
DefaultTableModel model = new DefaultTableModel(colssort,0);
while (rssort.next())
{
Object[] rowsort = new Object[columnCount];
for (i = 1 ; i <= columnCount ; i++)
{
rowsort[i-1] = rssort.getObject(i);
}
model.addRow(rowsort);
}
JTable table = new JTable(model);
model.fireTableDataChanged();
table.setCellSelectionEnabled(true);
table.setColumnSelectionAllowed(true);
table.setFillsViewportHeight(true);
table.setSurrendersFocusOnKeystroke(true);
table.setBounds(218,59,529,360);
frame.getContentPane().add(table);
model.fireTableDataChanged();
conn.close();
stmtsort.close();
rssort.close();
} catch (SQLException case1)
{case1.printStackTrace();
} catch (Exception case2)
{case2.printStackTrace();}
}
});
UPDATE
OK I managed to fix this issue with the getMetaData() but now the thing is that I dont use any ResultSet variables/instances and cant use next() method to create my DB.
String name = "SELECT * FROM consoles INNER JOIN hardware ON consoles.id=hardware.id ORDER BY consoles.name ?";
PreparedStatement psname = conn.prepareStatement(name);
String strin = JOptionPane.showInputDialog(null,"ASC or DESC order ? : ");
psname.setString(1,strin);
psname.executeUpdate();
ResultSetMetaData mdsort = psname.getMetaData();
int columnCount = mdsort.getColumnCount();
.
.
.
// error coming up here,because i deleted the ResultSet
while (psname.next())
.
.
.
Better make a bit more complex TableModel.
That is more optimal.
Keep the data from the ResultSet in an original TableModel.
Use a wrapping TableModel to sort, and maybe filter.
Use the ResultSetMetaData for the column type, if it is Number (Integer, BigDecimal, ...) then use that type instead of Object for the column type: gives a right aligned column.
Maybe first do an internet search for ResultSetTableModel; other peoply must have done it already.
try{
conn = DriverManager.getConnection("jdbc:mysql://localhost/test1?user=me&password=12345");
String strin = JOptionPane.showInputDialog(null,"ASC or DESC order ? : ");
stmtsortname = conn.createStatement();
rssortname = stmtsortname.executeQuery("SELECT * FROM consoles INNER JOIN hardware ON consoles.id=hardware.id ORDER BY consoles.name "+strin);
mdsortname = rssortname.getMetaData();
columnCount = mdsortname.getColumnCount();
String[] colssortname = new String[columnCount];
for (i=1;i<= columnCount;i++)
{
colssortname[i-1] = mdsortname.getColumnName(i);
}
model = new DefaultTableModel(colssortname,0);
while (rssortname.next())
{
Object[] rowsortname = new Object[columnCount];
for (i = 1 ; i <= columnCount ; i++)
{
rowsortname[i-1] = rssortname.getObject(i);
}
model.addRow(rowsortname);
}
table = new JTable(model);
model.fireTableDataChanged();
table.setCellSelectionEnabled(true);
table.setColumnSelectionAllowed(true)
table.setFillsViewportHeight(true);
table.setSurrendersFocusOnKeystroke(true);
table.setBounds(146,59,763,360);
frame.getContentPane().add(table);
model.fireTableDataChanged();
conn.close();
stmtsortname.close();
rssortname.close();
} catch (SQLException case1)
{
case1.printStackTrace();
}
catch (Exception case2)
{
case2.printStackTrace();
}
}
});

Getting next value from sequence

I have a bit of code here to get the next value of my sequence, but it is adding the total number of records onto the result each time.
I'm only learning about prepared Statements, I'm thinking this is something small, maybe rset.next() should be something else?
public void add( String title, String actor, String genre ) {
try {
String sql2 = "Select movie_seq.nextval from Movie";
pstmt = conn.prepareStatement(sql2);
rset = pstmt.executeQuery();
int nextVal = 0;
if(rset.next())
nextVal = rset.getInt(1);
String queryString = "Select MovieID, Title, Actor, Genre from Movie";
pstmt = conn
.prepareStatement(queryString,
ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_UPDATABLE);
rset = pstmt.executeQuery();
rset.moveToInsertRow();
rset.updateInt(1, nextVal);
rset.updateString(2, title);
rset.updateString(3, actor);
rset.updateString(4, genre);
rset.insertRow();
pstmt.executeUpdate();
} catch (SQLException e2) {
System.out.println("Error going to previous row");
System.exit(1);
}
}
Any help appreciated.
I think you don't need the call to pstmt.executeUpdate();
As stated in ResultSet doc, the function insertRow stores the row in the Dataset AND in the database.
The following code shows all that's necessary to add a new row:
rset.moveToInsertRow(); // moves cursor to the insert row
rset.updateString(1, "AINSWORTH"); // updates the
// first column of the insert row to be AINSWORTH
rset.updateInt(2,35); // updates the second column to be 35
rset.updateBoolean(3, true); // updates the third column to true
rset.insertRow();
rset.moveToCurrentRow();
Why dont you iterate using while rather than if . something like this
List lst = new ArrayList();
Someclass sc = new SomeClass(); //object of the class
String query = "SELECT * from SomeTable";
PreparedStatement pstmt = sqlConn.prepareStatement(query);
ResultSet rs = pstmt.executeQuery();
Role role = null;
while (rs.next()) {
String one = rs.getString(1);
String two = rs.getString(2);
boolean three = rs.getBoolean(3);
//if you have setters getters for them
sc.setOne(one);
sc.setTwo(two);
sc,setThree(three);
lst.add(sc)
}
//in the end return lst which is of type List<SomeClass>
}
Shouldn't you be doing this instead?:
String sql2 = "Select " + movie_seq.nextval + " from Movie";
As it is, it seems like you're passing a slightly bogus string into the SQL query, which is probably defaulting to the max index (not 100% positive on that). Then rs.next() is just incrementing that.

Deleting selected row in MySQL database through JTable

tb_records = jtable name
records = table name inside my database
Date = my first column
hey = substitute for my real password
mydatabase = name of my database
My problem is that, when I highlight a row in my JTable and delete it, it deletes all the rows. I want to delete the selected row only. Here's my code:
int row = tb_records.getSelectedRow();
DefaultTableModel model= (DefaultTableModel)tb_records.getModel();
String selected = model.getValueAt(row, 0).toString();
if (row >= 0) {
model.removeRow(row);
try {
Connection conn = (Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/mydatabase", "root", "hey");
PreparedStatement ps = conn.prepareStatement("delete from records where Date='"+selected+"' ");
ps.executeUpdate();
}
catch (Exception w) {
JOptionPane.showMessageDialog(this, "Connection Error!");
}
}
What could be the problem here? How can I delete a selected row in my database and not all the rows?
DefaultTableModel model = (DefaultTableModel) jTable.getModel();
int row = jTable.getSelectedRow();
String eve = jTable.getModel().getValueAt(row, 0).
String delRow = "delete from user where id="+eve;
try {
ps = myCon.getConnection().prepareStatement(delRow);
ps.execute();
JOptionPane.showMessageDialog(null, "Congratulation !!");
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e.getMessage());
}
1) Don't display your own message. Display the error message from the Exception as it will give a better explanation what the problem is.
2) Use a proper PreparedStatement for the SQL. You are less likely to make syntax errors. Something like:
String sql = "delete from records where Date= ?";
PreparedStatement stmt = connection.prepareStatement(sql);
stmt.setString( 1, selected );
stmt.executeUpdate();
I don't know much about SQL but maybe you need to pass a Date object not a String object since your where clause is using a Date?
The OP wrote:
SOLUTION: Pick a column with unique values. My Date column has the same values that's why it's deleting all my rows even though I set my row as getSelectedRow. Time_in = my 4th column with unique values.
change
String selected = model.getValueAt(row, 0).toString();
to
String selected = model.getValueAt(row, 3).toString();
and
PreparedStatement ps = conn.prepareStatement("delete from records where Date='"+selected+"' ");
to
PreparedStatement ps = conn.prepareStatement("delete from records where Time_in='"+selected+"' ");

Java PreparedStatement Wilcard doesn't work

I have DDBB with a table users and I'm trying to get fields user_id and user_pass by searching for user_name.
So, when I run the following query:
SELECT `user_id`, `user_pass` FROM `users` WHERE `user_name` LIKE '%aName%';
It returns, ie aName = "John":
+---------+-----------+
| user_id | user_pass |
+---------+-----------+
| 5 | "1234" |
+---------+-----------+
Ok, then I want to perform this using a PreparedStatement, for that reason I have made this function:
private final String QUERY_GETUSERNAME2 =
"SELECT `user_id`, `user_fname`"
+ " FROM `users`"
+ " WHERE `user_fname` LIKE ?;";
private String[][] getUsersInv(String usrName){
ArrayList<String[]> alAux = new ArrayList();
String[][] ret = null;
try{
PreparedStatement st = _conn.prepareStatement(QUERY_GETUSERNAME2);
st.setString(1, "'%"+usrName+"%'");
ResultSet rs = st.executeQuery();
while(rs.next()){
String[] asAux = {String.valueOf(rs.getInt(1)), rs.getString(2)};
alAux.add(asAux);
}//while
}catch(SQLException e){
e.printStackTrace(System.out);
}finally{
if (!alAux.isEmpty()){
ret = new String[alAux.size()][alAux.get(0).length];
for (int i = 0; i < alAux.size(); i++)
ret[i] = alAux.get(i);
}//fi
}
return ret;
}
As you can see, the function returns a String[][], so I check in a previous function if returns is or not null:
public void insertUsersInvTableModel(JTable table, String user){
DefaultTableModel model = (DefaultTableModel) table.getModel();
String[][] row = getUsersInv(user);
if (row != null)
model.addRow(row);
}
And this function is call from the listener for a JButton:
private void addUserActionPerformed(java.awt.event.ActionEvent evt) {
if (comboUsers.getSelectedIndex() != 0){
new Users(_conn).insertUsersInvTableModel(_target, String.valueOf(comboUsers.getSelectedItem()));
_target.validate();
_target.repaint();
setVisible(false);
}
}
As you can imagine, there's a JDialog with a JComboBox with all the users listed down.
As table users is AUTO_INCREMENT, the user_id has some gaps (or maybe it will have), and the only way to build the JComboBox was without relate user_id to JComboBox index.
But, the problem is that whenever I pick an item from the JComboBox, and I run the process to get the user_id and user_pass based on the item selected (nor the index), the ResultSet is always NULL.
Any idea?
Thanks.
replace
st.setString(1, "'%"+usrName+"%'");
with
st.setString(1, "%"+usrName+"%");
The single quotes are automatically added by the PreparedStatement. With the Quotes the query will look for the String '%usrname%' instead of %usrname%
try
st.setString(1, "%"+usrName+"%");
instead of
st.setString(1, "'%"+usrName+"%'");
SOLUTION
As Marco Forberg pointed, quotes used for envolve the string parameter (') are not compulsory. Removing them fix the issue.

ResultSet returns only last row into JTable

I have done enough searches to solve my problem which i have done partly but there's this one bug that keeps disturbing me.I am trying to fetch data from a database based on a condition.I have a table 'user_branch' with a foreign key column branchID which is supposed to fetch the coresponding branchNames in another table 'branches' and I am supposed to display the results into a JTable.When i do System.out.println i get all my results but it returns only the last row when i display in a JTable(branchJTable).This is the code i am using
int row = user2BAssignedJTable.getSelectedRow();
assignUserID.setText(user2BAssignedJTable.getModel().getValueAt(row, 0).toString());
user2BAssignedField.setText(user2BAssignedJTable.getModel().getValueAt(row, 1).toString());
try {
String userBrQry = "SELECT branchID FROM user_branch WHERE userID IN(?) ";
String brQ = "SELECT branchName FROM branches WHERE branchID IN(%s) ";
pstmt = con.prepareStatement(userBrQry);
pstmt.setString(1, assignUserID.getText());
results = pstmt.executeQuery();
results.last();
int nRows = results.getRow();
results.beforeFirst();
while (results.next()) {
String branchIDS = results.getString("branchID");
StringBuilder builder = new StringBuilder();
for (int i = 0; i < nRows; i++) {
builder.append("?");
if (i + 1 < nRows) {
builder.append(",");
}
}
brQ = String.format(brQ, builder.toString());
PreparedStatement ps = con.prepareStatement(brQ);
for (int i = 0; i < nRows; i++) {
ps.setString(i + 1, branchIDS);
}
ResultSet rs = ps.executeQuery();
//branchJTable.setModel(DbUtils.resultSetToTableModel(rs));
javax.swing.table.DefaultTableModel model = new javax.swing.table.DefaultTableModel();
model.setColumnIdentifiers(new String[]{"Branch Name"});
branchJTable.setModel(model);
while (rs.next()) {
String branchname = rs.getString("branchName");
model.addRow(new Object[]{branchname});
}
}
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e);
}
Forget about the first 3 rows as it is a another JTable event i use to get the userID to use as a condition for getting a particular user's branches assigned to him.
The branches assigned to a user is dynamic hence using StringBuilder.
I am supposed to display the results into another JTable called branchJTable which only displays the last row.Any HELP would be appreciated!
From your question, I think you should declare the JTable
javax.swing.table.DefaultTableModel model = new javax.swing.table.DefaultTableModel();
model.setColumnIdentifiers(new String[]{"Branch Name"});
branchJTable.setModel(model);
before your first loop -
i.e. before while (results.next()) { in your code.
Otherwise in loop, for each loop execution,
the JTable Model is initialising and you are getting the last inserted row in Jtable.

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