Tasks studies - laboratory
The task is to create a program using JDBC to connect to a database. We will use SQLite as the database system.
To use JDBC with a specific database system, a driver is necessary. The driver for SQLite can be downloaded from this link. Save the downloaded file in a local folder.
Create a project in IntelliJ via File > New Project (a regular Java project).
In the main program file, place the following code:
import java.sql.*;
public class Main {
public static void main(String args[]) {
Connection c = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:test.db");
} catch (Exception e) {
System.err.println(e.getClass().getName() + ": " + e.getMessage());
System.exit(0);
}
System.out.println("Opened database successfully");
}
}
To run the program, the downloaded driver must be added to the project configuration.
Do this by selecting File > Project Structure > Project Settings > Modules > Dependencies.
Click + > JAR or Directory and select the driver file sqlite-jdbc-VERSION_NUMBER.jar that you downloaded earlier.
After adding the driver to the configuration, the project can be run. If everything works correctly, the console will display: “Opened database successfully.” At the same time, the main project folder will contain a file test.db (the program will create this file if it does not already exist).
In the next version of this program, we will create a table in the database. The main method should look like this:
public static void main(String args[]) {
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:test.db");
System.out.println("Opened database successfully");
stmt = c.createStatement();
String sql = "CREATE TABLE COMPANY " +
"(ID INT PRIMARY KEY NOT NULL," +
" NAME TEXT NOT NULL, " +
" AGE INT NOT NULL, " +
" ADDRESS CHAR(50), " +
" SALARY REAL)";
stmt.executeUpdate(sql);
stmt.close();
c.close();
} catch (Exception e) {
System.err.println(e.getClass().getName() + ": " + e.getMessage());
System.exit(0);
}
System.out.println("Table created successfully");
}
The program can only be run once. On subsequent runs, it will generate an error because the table already exists.
The next version of the program demonstrates adding data to the table. The main method should look like this:
public static void main(String args[]) {
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:test.db");
c.setAutoCommit(false);
System.out.println("Opened database successfully");
stmt = c.createStatement();
String sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " +
"VALUES (1, 'Paul', 32, 'California', 20000.00 );";
stmt.executeUpdate(sql);
sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " +
"VALUES (2, 'Allen', 25, 'Texas', 15000.00 );";
stmt.executeUpdate(sql);
sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " +
"VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );";
stmt.executeUpdate(sql);
sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " +
"VALUES (4, 'Mark', 25, 'Rich-Mond', 65000.00 );";
stmt.executeUpdate(sql);
stmt.close();
c.commit();
c.close();
} catch (Exception e) {
System.err.println(e.getClass().getName() + ": " + e.getMessage());
System.exit(0);
}
System.out.println("Records created successfully");
}
The next version of the program demonstrates reading data:
public static void main(String args[]) {
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:test.db");
c.setAutoCommit(false);
System.out.println("Opened database successfully");
stmt = c.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM COMPANY;");
while (rs.next()) {
int id = rs.getInt("id");
String name = rs.getString("name");
int age = rs.getInt("age");
String address = rs.getString("address");
float salary = rs.getFloat("salary");
System.out.println("ID = " + id);
System.out.println("NAME = " + name);
System.out.println("AGE = " + age);
System.out.println("ADDRESS = " + address);
System.out.println("SALARY = " + salary);
System.out.println();
}
rs.close();
stmt.close();
c.close();
} catch (Exception e) {
System.err.println(e.getClass().getName() + ": " + e.getMessage());
System.exit(0);
}
System.out.println("Operation done successfully");
}
The next version of the program is a data update:
public static void main( String args[] ) {
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:test.db");
c.setAutoCommit(false);
System.out.println("Opened database successfully");
stmt = c.createStatement();
String sql = "UPDATE COMPANY set SALARY = 25000.00 where ID=1;";
stmt.executeUpdate(sql);
c.commit();
ResultSet rs = stmt.executeQuery( "SELECT * FROM COMPANY;" );
while ( rs.next() ) {
int id = rs.getInt("id");
String name = rs.getString("name");
int age = rs.getInt("age");
String address = rs.getString("address");
float salary = rs.getFloat("salary");
System.out.println( "ID = " + id );
System.out.println( "NAME = " + name );
System.out.println( "AGE = " + age );
System.out.println( "ADDRESS = " + address );
System.out.println( "SALARY = " + salary );
System.out.println();
}
rs.close();
stmt.close();
c.close();
} catch ( Exception e ) {
System.err.println( e.getClass().getName() + ": " + e.getMessage() );
System.exit(0);
}
System.out.println("Operation done successfully");
}
A version of the program that demonstrates deleting a row from an array.
public static void main( String args[] ) {
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:test.db");
c.setAutoCommit(false);
System.out.println("Opened database successfully");
stmt = c.createStatement();
String sql = "DELETE from COMPANY where ID=2;";
stmt.executeUpdate(sql);
c.commit();
ResultSet rs = stmt.executeQuery( "SELECT * FROM COMPANY;" );
while ( rs.next() ) {
int id = rs.getInt("id");
String name = rs.getString("name");
int age = rs.getInt("age");
String address = rs.getString("address");
float salary = rs.getFloat("salary");
System.out.println( "ID = " + id );
System.out.println( "NAME = " + name );
System.out.println( "AGE = " + age );
System.out.println( "ADDRESS = " + address );
System.out.println( "SALARY = " + salary );
System.out.println();
}
rs.close();
stmt.close();
c.close();
} catch ( Exception e ) {
System. err.println( e.getClass().getName() + ": " + e.getMessage() );
System.exit(0);
}
System.out.println("Operation done successfully");
}
``` ## Task
Based on the above examples, you should create a program with the following functions:
### [Task 1.](https://github.com/dawidolko/Programming-Java/blob/master/Example/Lab5/zadania/src/ task1.java)
A function that creates a table with a list of students' attendance at online classes. The table should include:
a. Teacher
b. Subject name
c. Student name and surname,
d. Album number
e. Date of classes
f. Login time
g. Logout time
h. Length of time spent in the session.
### [Task 2.] (https://github.com/dawidolko/Programming-Java/tree/master/Example/Lab5/zadania/src)
A function that adds a student to the attendance list. During the addition, the
attendance data should be filled in
### [Task 3.] (https://github.com/dawidolko/Programming-Java/tree/master/Example/Lab5/zadania/src)
A function that displays the attendance of all students in classes