[英]How to Copy a Data Row from my Student Table to another table (Student Record)?
我有一个使用 java 的登录系统,我的系统有最后一个问题。
当我仅在 JTextField 中键入和登录学生的学生 ID 号时,它将在文本字段中显示他或她的名字和姓氏。 这是我的学生登录系统。
我的问题是,当我登录他或她的学生 id 时,我想复制学生的数据,如学生 id、名字、中间名、姓氏,并插入到 PMA 中的学生记录表中。 这是我的代码:
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/studentdatabase","root","");
String student_id = txtStudent_ID.getText();
String sql = "INSERT INTO 'studentrecord' (stud_id, first_name, middle_name, last_name) "
+ "SELECT firstname, middlename, lastname FROM 'student' WHERE student_id = '" + student_id + "' ";
if (student_id.length() > 0) {
Statement st = conn.prepareStatement(sql);
ResultSet rs = st.executeQuery(sql);
if (student_id.length() > 0) {
if (rs.next()) {
String firstname = rs.getString(3);
String lastname = rs.getString(5);
txtFirstName.setText(firstname);
txtLastName.setText(lastname);
JOptionPane.showMessageDialog(null, "Logged in", "Success",
JOptionPane.INFORMATION_MESSAGE);
} else {
JOptionPane.showMessageDialog(null, "Sorry!, No data found for this ID", "Student ID",
JOptionPane.ERROR_MESSAGE);
JOptionPane.showMessageDialog(null, "Enter a Valid ID", "Student ID Information",
JOptionPane.INFORMATION_MESSAGE);
txtStudent_ID.setText("");
}
}
}
} catch (Exception ex) {
JOptionPane.showMessageDialog(null, "SQL Syntax should be reviewed", "Database",
JOptionPane.ERROR_MESSAGE);
}
它将有一个错误,它说“应该审查 SQL 语法”需要帮助。
我不知道 java,所以相反,这是一个有效的 MySQL 查询示例:
INSERT INTO studentrecord
(first_name, middle_name, last_name)
SELECT firstname, middlename, lastname
FROM student WHERE student_id = 'student_id'
或者
INSERT INTO studentrecord
(stud_id,first_name, middle_name, last_name)
SELECT stud_id,firstname, middlename, lastname
FROM student WHERE student_id = 'student_id'
( stud_id
和student_id
不同,只有你自己知道怎么解决!)
尝试转义'
如下
"INSERT INTO \'studentrecord\' (stud_id, first_name, middle_name, last_name) "
+ "SELECT firstname, middlename, lastname FROM \'student\' WHERE student_id = \'"+ student_id + "\' ";
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