so this is my table
CREATE TABLE "client" (
"id" INTEGER,
"name" TEXT COLLATE NOCASE,
"surname" TEXT COLLATE NOCASE,
"number" TEXT UNIQUE COLLATE NOCASE,
"car_brand" TEXT,
"modele" TEXT,
"phone_nbr" TEXT,
PRIMARY KEY("id" AUTOINCREMENT));
when im adding a new statment from my java application i can add only one time NULL to the column number but i can add many nulls from the db browser
this is the code that i use
String number = tf_number.getText();
if(tf_number.getText().trim().isEmpty())
number = null;
String name = tf_name.getText();
String surname = tf_surname.getText();
String phoneNbr = tf_phoneNbr.getText();
String car_brand = tf_brand.getText();
String modele = tf_modele.getText();
Client c = new Client(name, surname, number, car_brand, modele, phoneNbr);
ClientCRUD pcd = new ClientCRUD();
pcd.addClient(p);
and this is the sql error
[SQLITE_CONSTRAINT_UNIQUE] A UNIQUE constraint failed (UNIQUE constraint failed: client.number)
this is the addClient() fonction
public void addClient(Client t) {
try {
String requete = "INSERT INTO CLIENT(name,surname,number,car_brand,MODELE,phone_nbr)"
+ "VALUES ('"+t.getClientName()+"','"+t.getClientSurname()+"','"+t.getNumber()+"',"
+ "'"+t.getCarBrand()+"','"+t.getModele()+"','"+t.getPhone()+"')";
Statement st = MyConnection.getInstance().getCnx()
.createStatement();
st.executeUpdate(requete);
System.out.println("Client added");
} catch (SQLException ex) {
System.out.println(ex.getMessage());
}
}
any solution ?
public void save(Person person) {
String query = "INSERT INTO person_info (" +
" name_p, " +
" age, " +
" address, " +
" email " +
")" +
"VALUES(?, ?, ?, ?)";
try(Connection connection = dbConnection.getConnection()) {
PreparedStatement prepStatement = connection.prepareStatement(query);
prepStatement.setString(1, person.getName());
prepStatement.setInt(2, person.getAge());
prepStatement.setString(3, person.getAddress());
prepStatement.setString(4, null);
prepStatement.execute();
}
catch (SQLException e){
e.printStackTrace();
}
}
##This will solve your problem
You code inserts the string "null" and not a real null like your browser do.
So there can be only 1 string with value "null" in that unique column.
You can use preparedStatement with parameters instead of the statement you use.
E.g:
PreparedStatement preparedStatement = connection.prepareStatement(sql))
This answers how to insert null using prepared statement: Insert null using prepared statement
And your sql string for the query should have the parameters.
See more about prepared statements: Prepared Statements Tutorial
Related
I have the following code:
public void updateAccount(String username, String name, String address, String aboutMe,
String id) {
String sql = "update Account set username = ?, \n"
+ " [Full_Name] = ?,\n"
+ " [Address] = ?,\n"
+ " [about_me] = ?\n"
+ " where id = ?";
try {
PreparedStatement ps = connection.prepareStatement(sql);
ps.setString(1, username);
ps.setString(2, name);
ps.setString(3, address);
ps.setString(4, aboutMe);
ps.setString(5, id);
ps.executeUpdate();
} catch (Exception ex) {
Logger.getLogger(AccountDao.class.getName()).log(Level.SEVERE, null, ex);
}
}
But when I change something like username, fullname in my web, they are still not updated and show the following error:
Severe: com.microsoft.sqlserver.jdbc.SQLServerException: Cannot insert the value NULL into
column 'username', table 'FERA_ONL_LEARNING.dbo.Account'; column does not allow nulls. UPDATE
fails. at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDatabaseError(SQLServerException.java:217)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.getNextResult(SQLServerStatement.java:1655)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.doExecutePreparedStatement(SQLServerPreparedStatement.java:440)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement$PrepStmtExecCmd.doExecute(SQLServerPreparedStatement.java:385)
at com.microsoft.sqlserver.jdbc.TDSCommand.execute(IOBuffer.java:7505)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.executeCommand(SQLServerConnection.java:2445)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeCommand(SQLServerStatement.java:191)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeStatement(SQLServerStatement.java:166)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.executeUpdate(SQLServerPreparedStatement.java:328)
at dao.AccountDao.updateAccount(AccountDao.java:142)
at controller.UserProfileController.doPost(UserProfileController.java:91)
I'm sure I changed their values and it can't be NULL.
How to fix this error?
Have you tried printing the result of your dynamic query? You could add a system.out.println(sql) before ps.executeUpdate(), to verify that your variables are being assigned the value correctly.
I estimate by how the sql is concatenated that it is not taking the positions correctly and by default the setString returns NULL.
What's wrong with the code, no errors but still it's not saving to database, where did it go wrong?
Even if the database is created, the code won't store the values
JButton btnSave = new JButton("SAVE");
btnSave.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// Get Breed and age entered by user
String breed = textBreed.getText();
String breed_age = textAge.getText();
// Convert age into integer
int age = Integer.parseInt(breed_age);
// Connection
try {
//open connection
Class.forName("com.mysql.cj.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost/animal_db", "root", "root");
// Insert data into table
Statement stm = con.createStatement();
String dog_table = "CREATE TABLE IF NOT EXISTS breedtest" +
"(id INT NOT NULL AUTO_INCREMENT," +
"breed VARCHAR(30)," +
"age INT," +
"PRIMARY KEY (id))";
stm.executeUpdate(dog_table);
String sql = "INSERT INTO breedtest VALUES ('"+textBreed.getText()+"', "+textAge.getText()+")";
// Execute Statement
stm.executeUpdate(sql);
// display message of record inserted
JOptionPane.showMessageDialog(btnSave, "Record added");
textBreed.setText("");
textAge.setText("");
//Close connection
con.close();
}catch(Exception E) {
}
}
});
textBreed & textAge are text field from the GUI
here is a creen shot of the GUI.
enter image description here
I have amended the following lines, and it works fine
// Insert data into table
Statement stm = con.createStatement();
String dog_table = "CREATE TABLE IF NOT EXISTS breedtest" +
"(id INT NOT NULL AUTO_INCREMENT," +
"breed VARCHAR(30)," +
"age INT," +
"PRIMARY KEY (id))";
stm.executeUpdate(dog_table);
String sql = "INSERT INTO breedtest" + "(breed, age)" + "VALUES(?, ?)";
PreparedStatement brd = con.prepareStatement(sql);
brd.setString(1, textBreed.getText());
brd.setString(2, textAge.getText());
brd.execute();
data got captured in database with the confirmation message.
Displayed message
Database table
This line of code is not executing
String sql = "INSERT INTO breedtest" + "(breed, age)" + "VALUES ("+textBreed.getText()+", "+textAge.getText()+")";
but this one is.
String sql = "INSERT INTO breedtest" + "(breed, age)" + "VALUES(?, ?)";
I understand that in my first code I omitted to name the columns, thanks for flagging this.
Could someone explain me which line of code is associating the "VALUES(?, ?)" to the textfield.
You need to modify your Insert query with the following
String sql = "INSERT INTO breedtest(breed, age) VALUES ('"+textBreed.getText()+"', "+textAge.getText()+")";
I'm trying to figure out why this code is throwing an SQL exception. When I run this code it prints "Bad SQL in customer insert ps", which is the message in that inner catch block. I've got multiple prepared statements with SQL inserts like this both in this class and also elsewhere in my application. They're all working fine. I've looked through this one over and over again, and I can't figure out why this one is throwing an exception.
try {
Connection conn = DBconnection.getConnection();
PreparedStatement ps = conn.prepareStatement("SELECT customerId FROM customer WHERE customerName=\"" + name + "\";");
System.out.println(ps.toString());
ResultSet rs = ps.executeQuery();
if (rs.next()) {
customerId = rs.getString("customerId");
}
try {
PreparedStatement customerInsert = DBconnection.getConnection().prepareStatement("INSERT "
+ "INTO customer (customerName, addressId, active, createDate, createdBy, lastUpdate, lastUpdateBy)"
+ "VALUES(\"" + name + "\", " + addressId + ", " + active + ", UTC_TIMESTAMP(), \"" + LogInController.getUserName() + "\", UTC_TIMESTAMP(), \"" + LogInController.getUserName() + "\");");
customerInsert.executeUpdate();
System.out.println(customerInsert.toString());
System.out.println(rs.toString());
} catch (SQLException sq) {
System.out.println("Bad SQL in customer insert ps");
}
} catch (SQLException customerIdException) {
System.out.println("Bad SQL in customer ps");
}
You're using PreparedStatement as though you were using Statement. Don't put the parameters in the SQL, put in placeholder ? marks. Then use the various setXyz methods (setString, setInt, etc.) to fill in the parameters:
PreparedStatement customerInsert = DBconnection.getConnection().prepareStatement(
"INSERT INTO customer (customerName, addressId, active, createDate, createdBy, lastUpdate, lastUpdateBy)" +
"VALUES(?, ?, ?, ?, ?, ?, ?);"
);
customerInsert.setString(1, name);
customerInsert.setInt(2, addressId);
// ...etc. Notice that the parameter indexes start with 1 rather than 0 as you might expect
Can anybody point out what's wrong with my code? I am trying to update an attribute but I got an error
com.mysql.jdbc.MysqlDataTruncation: Data truncation: Data too long for
column 'phone' at row 1
Is there anything wrong with the SQL command? Thank you!
String queryString = "";
String selectedItem = (String) searchTypeCmb.getSelectedItem();
String searchTerm = searchTermField.getText();
String id = theId.getText();
textArea.setText("");
if ("Phone".equals(selectedItem)) {
queryString = "UPDATE person SET phone = '" + (searchTerm) +
" WHERE driverID = " + (id) + "'";
}
else if ("Address".equals(selectedItem)) {
queryString = "UPDATE person SET address = '" + (searchTerm) +
" WHERE driverID = " + (id) + "'";
}
try {
connection = DriverManager.getConnection("jdbc:mysql://localhost/dealer", "root", "admin");
statement = connection.createStatement();
statement.executeUpdate(queryString);
Here is my DB schema
create table person
( driverID int unsigned not null primary key,
firstName char(20) not null,
lastName char(20) not null,
address char(30) not null,
phone char(20)
);
create table cars
( license char(10) not null,
brand char(20) not null,
model char(20) not null,
year char(10),
status char(10) not null,
carID int unsigned not null primary key
);
To start with, your missing closing quotes around your text...
"UPDATE person SET phone = '" + (searchTerm) + " WHERE driverID = " + (id) + "'"
^-----------------------------^
Which you probably want to be
"UPDATE person SET phone = '" + (searchTerm) + "' WHERE driverID = " + (id)
But having said that, I'd strongly encourage you to use PreparedStatements instead.
String queryString = "";
String selectedItem = (String) searchTypeCmb.getSelectedItem();
String searchTerm = searchTermField.getText();
String id = theId.getText();
textArea.setText("");
try (Connection connection = DriverManager.getConnection("jdbc:mysql://localhost/dealer", "root", "admin")) {
PreparedStatement stmt = null;
if ("Phone".equals(selectedItem)) {
stmt = connection.prepareStatement("UPDATE person SET phone = ? WHERE driverID = ?");
} else if ("Address".equals(selectedItem)) {
stmt = connection.prepareStatement("UPDATE person SET address = ? WHERE driverID = ?");
}
if (stmt != null) {
stmt.setString(1, searchTerm);
stmt.setString(2, id);
stmt.executeUpdate();
}
See Using Prepared Statements for more details...
If you have the message
com.mysql.jdbc.MysqlDataTruncation: Data truncation: Data too long for column 'phone'
The data that you are writing in the column "phone" is longer than the maximum length of that field on the database.
So you can:
Truncate the phone value before inserting it in the database
Alter your column length in the database
I'm trying to check if the "Username" and "Email" arguments in my constructor are existed in the SQL Table.
this is my code:
public DB(String usr, String eml, String pwd) {
this.usr = usr;
this.eml = eml;
this.pwd = pwd;
String jdbcUrl = "jdbc:mysql://localhost:3306/registered";
String jdbcUser = "....";
String jdbcPassword = "....";
try {
Class.forName("com.mysql.jdbc.Driver");
connection = DriverManager.getConnection(jdbcUrl, jdbcUser,
jdbcPassword);
statement = connection.createStatement();
now , if i use SELECT with two columns, like this:
String command = "SELECT UserName,Email FROM users WHERE UserName LIKE '" + this.usr.toString() + "';";
resultSet = statement.executeQuery(command);
and then do my loop for resultSet... like this:
while (resultSet.next()) {
if (usr.equalsIgnoreCase(resultSet.getString("UserName"))) {
System.out.println("UserName : " + this.usr + " is taken!");
}
else if (eml.equalsIgnoreCase(resultSet.getString("Email"))) {
System.out.println("Email : " + this.eml + " is taken!");
}
else {
System.out.println("Email : " + this.eml + " and UserName : " + this.usr + " are AVAILABLE!");
command = "INSERT users SET UserName = '" + this.usr.toString() + "',Email = '" + this.eml.toString() + "',Password = '" + this.pwd.toString() + "',Status = '0' ,Connected = '1';";
statement.executeUpdate(command);
}
}
} catch (SQLException e) {
System.out.println("SQLException: " + e.getMessage());
System.out.println("Vendor error: " + e.getErrorCode());
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
the
resultSet.next()
only runs over the "FIRST" column which means
if the "usr" exists in the table it works,
but if the "usr" does not exist in the table, the other two if statements does-not work ..
,... i want to check both first column and second,.. and maybe third or more soon.. , any help?
Your WHERE clause only tests for the UserName, so if the UserName doesn't match this.usr.toString(), the resultSet will be empty, so the while loop won't be entered.
You should change the query to match all the fields you care about - something like - "SELECT UserName,Email FROM users WHERE UserName = ... OR Email = ..."
If the resultSet is empty, you'll know that you can insert the new record. Otherwise, you can check which of the fields (UserName, Email) is already taken.
One more thing you should be aware of - executing a SQL statement without PreparedStatement makes your code vulnerable to SQL injection attacks.
You should change your code to something like this :
PreparedStatement pstmt = con.prepareStatement("SELECT UserName,Email FROM users WHERE UserName = ? OR Email = ?");
pstmt.setString(1, this.usr);
pstmt.setString(2, this.eml);
resultSet = pstmt.executeQuery();
You should change your INSERT statement similarly to use PreparedStatement.