在mysql表中插入数据时出错

Question

String pass=new String(pf1.getPassword());

try {
    Connection myConn=DriverManager.getConnection("jdbc:mysql://localhost:3306/javaproject","root","noor1032");
    PreparedStatement myStat=myConn.prepareStatement("insert into user_info (username,password,email_id)"+"values(?,?,?)");
    myStat.setString(1, tf1.getText());
    myStat.setString(2, pass);
    myStat.setString(3, tf2.getText());
    myStat.execute();
    myConn.close();
}   
catch(Exception f)
{
    System.err.println("Got an exception!");
    System.err.println(f.getMessage());
}

I want to insert data entered by user in a JFrame to my sql database. tf1 and tf2 are textfields for username and email_id, respectively. When I execute this statement an exception occurs saying that

Field 'id' does not have a default value

id is a column in my database denoting numbers like 1,2,3 and so on. Please help me.

Answer 1

您必须在 mysql 中将 ID 设置为 Auto Increment。它会起作用

Answer 2

Although you haven't shared your table's structure, I guess that id is a PRIMARY KEY but you missed AUTO_INCREMENT configuration. In your database, run the following statement

ALTER TABLE user_info MODIFY COLUMN id INT auto_increment