Develop Reference

I want to add a search in my sql database, function to get the name by the id creates an error

I have a music database so I'll need a search function, now when entering into the search bar, I get the error : "Invalid argument in JDBC call: parameter index out of range: 1"
public static Song getSongByName(String name)
{
String sql =
"SELECT songID FROM Song "+
"WHERE name = '?'; ";
Connection conn = Connections.getConnection();
Song erg = null;
try
{
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1,name);
ResultSet rs = pstmt.executeQuery();
rs.next();
int id = rs.getInt (1);
name = rs.getString (2);
erg = new SongImpl(id,name);
rs.close();
pstmt.close();
}
catch(SQLException exc)
{
System.err.println("Fehler: in SQL-Aufruf");
System.err.println("["+sql+"]");
exc.printStackTrace();
System.exit(6);
}
Connections.putConnection(conn);
return erg;
}

It seems like you are selecting just one column instead of two.
The correct SQL query would be:
SELECT songID, songName FROM Song WHERE name = '?';
Try this:
public static Song getSongByName(String name)
{
String sql =
"SELECT songID, songName FROM Song "+
"WHERE name = ?";
Connection conn = Connections.getConnection();
Song erg = null;
try
{
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1,name);
ResultSet rs = pstmt.executeQuery();
rs.next();
int id = rs.getInt(1);
String name = rs.getString(2);
erg = new SongImpl(id, name);
rs.close();
pstmt.close();
}
catch(SQLException exc)
{
System.err.println("Fehler: in SQL-Aufruf");
System.err.println("["+sql+"]");
exc.printStackTrace();
System.exit(6);
}
Connections.putConnection(conn);
return erg;
}
Let me know if that helped :)

Look onto examples https://docs.oracle.com/javase/tutorial/jdbc/basics/prepared.html
Try to remove single quotes:
String sql =
"SELECT songID FROM Song "+
"WHERE name = ?; ";
You should use string parameters without quotes because your statement interpreted as a SQL query without parameters.

JAVA GUI - GET and SHOW DATA FROM MYSQL

I am working on a GUI app with MySQL access. When user enters some data in JTextField 'VendorID', I want it to be searched in the database, find the proper line with information and show all the columns in other JtextFields seperately. Actually I wanted this data to be showed in JLabel but unsuccessful, so trying now with JtextFields. Appreciate any help from you.
public void findVendor() {
String vatEntered = vendorID.getText();
try
{
String myDriver = "com.mysql.jdbc.Driver";
String myUrl = "jdbc:mysql://localhost:3306/masterdata_db?autoReconnect=true&useSSL=false";
Class.forName(myDriver);
Connection conn = DriverManager.getConnection(myUrl, "root", "");
Statement st = conn.createStatement();
String check = "SELECT * FROM vendorcreation WHERE VAT = 'vatEntered' ";
ResultSet resultSet = st.executeQuery(check);
boolean status = true;
if(resultSet.next()==status){
nameSelected.setText(resultSet.getString(1));
adressSelected.setText(resultSet.getString(2));
countrySelected.setText(resultSet.getString(3));
vatSelected.setText(resultSet.getString(4));
ptermsSelected.setText(resultSet.getString(5));
conn.close();
}
else {
JOptionPane.showMessageDialog(null, "NO DATA FOUND! FIRST YOU MUST CREATE IT", "Inane error",JOptionPane.ERROR_MESSAGE);
dispose();
new CreateVendor().setVisible(true);
}
}
catch (Exception e)
{
e.printStackTrace();
}
}

From what I'm understanding, you're having trouble executing the statement?
You need to set up the statement as following:
String check = "SELECT * FROM vendorcreation WHERE VAT = " +vatEntered ;
But it is better to use a prepared statement instead.
String check = "SELECT * FROM vendorcreation WHERE VAT = ?";
PreparedStatement st = conn.prepareStatement(check);
st.setString(1, vatEntered);
ResultSet resultSet = st.executeQuery();
As for categorizing data, the order seems to depend on the order that the column is in the database. What you can also do is to manually set the result by changing the statement:
String check = "SELECT (column1, column2) FROM vendorcreation WHERE VAT = ?"//etc
where resultSet.getString(1); would be data from column1.

Can't print information from SQL in Java

The user must choose a Resort ID from the table that is displayed and the make a booking. I can't seem to find my problem, I want to print the name of the Resort that they are making a booking at.
String x = jTextFieldID.getText();
Integer Resort = Integer.valueOf(x);
int resort = Integer.parseInt(x);
String sql = "SELECT RESORT_NAME FROM LouwDataBase.Resorts WHERE ID = "+Resort;
try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
pstmt.setInt(1, resort);
try (ResultSet rs = pstmt.executeQuery()) {
if (rs.next()) {
String resortName = rs.getString("RESORT_NAME");
JOptionPane.showMessageDialog(null,
"You want to book at " + resortName);
}

You have to use rs.next() :
ResultSet rs = pstmt.executeQuery(sql);
String resortName = "";
if(rs.next()){//<<-----------------------------
resortName = rs.getString("RESORT_NAME");
}
JOptionPane.showMessageDialog(null, "You want to book at "+resortName);
If you want to get many results you can use while(rs.next){...} instead.
Note? for a good practice, don't use upper letter in beginning for the name of your variables ResortName use this instead resortName

You need to test over the ResultSet result before trying to read from it:
if(rs.next()) {
String ResortName = rs.getString(1);
JOptionPane.showMessageDialog(null, "You want to book at "+ResortName);
}
And you can use getString(1) to get the RESORT_NAME, check ResultSet .getString(int index) method for further details.

The error is that sql is passed to Statement.executeQuery(String) too, instead of the PreparedStatement.executeQuery().
int resort = Integer.parseInt(x);
//String sql = "SELECT RESORT_NAME FROM LouwDataBase.Resorts WHERE ID = ?";
String sql = "SELECT RESORT_NAME FROM LouwDataBase.Resorts WHERE ID = " + resort;
try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
//pstmt.setInt(1, resort);
try (ResultSet rs = pstmt.executeQuery()) {
if (rs.next()) {
String resortName = rs.getString("RESORT_NAME");
JOptionPane.showMessageDialog(null,
"You want to book at " + resortName);
}
}
} catch (SQLException ex) {
Logger.getLogger(Booking.class.getName()).log(Level.SEVERE, null, ex);
}
Commented is the alternative usage of a prepared statement (as normally used).
Also you should close statement and result set, which can be done automatically with try-with-resources as above.
Oh, oversaw almost, that rs.next() must be called. (The others already mentioned.)

Using ResultSet to compare result within IF Statement (JAVA)

I have this piece of code where I prompt the user to enter the depID to edit a department and then through the IF statement I have done it displays either saved or department doesn't exists. Now my problem is that it's going directly to the else statement. When I used debugging I noticed that the RS (ResultSet) is only comaring the users input to the first row of the table which is AOL.
try{
String value1 = txt_depID.getText();
String value2 = txt_depName.getText();
String sql = "Update tblDepartment set depID = '"+value1+"' , depName = '"+value2+"' where depID = '"+value1+"'";
String sql1 = "Select depID, depName from tblDepartment";
Class.forName(driver);
conn = DriverManager.getConnection(url);
ps = conn.prepareStatement(sql1);
rs = ps.executeQuery();
ps = conn.prepareStatement(sql);
ps.execute();
if(rs.next()){
String depi = rs.getString("depID"); //Issue: only reading first row
if(depi.equals(value1)){
JOptionPane.showMessageDialog(null, "Entry Saved");
}
else{
JOptionPane.showMessageDialog(null, "Department doesn't exist");
}
}
} catch (Exception e){
JOptionPane.showMessageDialog(null, e);
}

You can do this in one cycle. You should be using executeUpdate.
String sql = "Delete from tblEmployee where staffNo=?";
String sql1 = "Select * from tblEmployee";
Class.forName(driver);
conn = DriverManager.getConnection(url);
ps = conn.prepareStatement(sql1);
int result = ps.executeUpdate();
if (result > 0) {
// success
}
Here's what executeUpdate results:
Returns: either (1) the row count for SQL Data Manipulation Language
(DML) statements or (2) 0 for SQL statements that return nothing

how to fix "This ResultSet is closed " error?

I want to use two sql query in my java code. the first query retain all row of table2 and the second one get it's rows one by one. I wrote follow code but it face to "This ResultSet is closed, it means rs ResultSet " error. How can I fix?
try{
String sqlSelectTable2 = "SELECT * FROM table2;";
ResultSet rs = stmt.executeQuery(sqlSelectTable2);
while (rs.next()) {
String strLineId = rs.getString(1);
String strPoints = rs.getString(2);
String sqlWithin = "SELECT ST_Within(ST_GeometryFromText('POINT( ),ST_GeomFromText('POLYGON((443425 4427680, 441353 4427680, 441368 4426075, 443762 4426149, 443425 4427680))', 4326));";
ResultSet rsWithin = stmt.executeQuery(sqlWithin);
} // end while ... **It get error when it is reading second ResultSet **
} catch (Exception e) {
System.out.println(e.getMessage());
}

You need to create separate PreparedStatement object for inner query
try{
String sqlSelectTable2 = "SELECT * FROM table2;";
ResultSet rs = stmt.executeQuery(sqlSelectTable2);
while (rs.next()) {
String strLineId = rs.getString(1);
String strPoints = rs.getString(2);
PreparedStatement preparedStatement = null;
String sqlWithin = "SELECT ST_Within(ST_GeometryFromText('POINT( ),ST_GeomFromText('POLYGON((443425 4427680, 441353 4427680, 441368 4426075, 443762 4426149, 443425 4427680))', 4326));";
preparedStatement = dbConnection.prepareStatement(sqlWithin);
ResultSet rsWithin = preparedStatement.executeQuery();
} // end while ... **It get error when it is reading second ResultSet **
} catch (Exception e) {
System.out.println(e.getMessage());
}