IDEA에서 데이터베이스 SQlite를 추가, 삭제, 수정 및 확인하는 기본 작업

Sqlite 데이터베이스의 직원 테이블(employee)의 데이터가 그림에 표시되어 있는 것으로 알려져 있습니다.

 사용할 수 있는 스크립트는 다음과 같습니다. (이에 따라 변경할 수도 있습니다.)

create table EMPLOYEE
(
  EMP_ID   VARCHAR2(5),
  EMP_NAME VARCHAR2(20),
  JOB      VARCHAR2(10),
  SALARY   NUMBER(7,2),
  DEPT     VARCHAR2(2)
)
;

insert into EMPLOYEE (EMP_ID, EMP_NAME, JOB, SALARY, DEPT)
values ('1', '王楠', 'clerk', 4300, '10');
insert into EMPLOYEE (EMP_ID, EMP_NAME, JOB, SALARY, DEPT)
values ('2', '张静', 'clerk', 4300, '10');
insert into EMPLOYEE (EMP_ID, EMP_NAME, JOB, SALARY, DEPT)
values ('3', '李刚', 'manager', 5000, '20');
insert into EMPLOYEE (EMP_ID, EMP_NAME, JOB, SALARY, DEPT)
values ('4', '马明', 'manager', 5000, '20');

데이터베이스의 연결 및 동작을 3개의 자바 클래스로 나누어 작성하며, 자바 파일은 다음과 같습니다.

Employee.java

package sql;

public class Employee {
    private String empID;
    private String empName;
    private String job;
    private String salary;
    private String dept;

    public Employee() {
    }

    public Employee(String empID, String empName, String job, String salary, String dept) {
        this.empID = empID;
        this.empName = empName;
        this.job = job;
        this.salary = salary;
        this.dept = dept;
    }

    public String getEmpID() {
        return empID;
    }

    public void setEmpID(String empID) {
        this.empID = empID;
    }

    public String getEmpName() {
        return empName;
    }

    public void setEmpName(String empName) {
        this.empName = empName;
    }

    public String getJob() {
        return job;
    }

    public void setJob(String job) {
        this.job = job;
    }

    public String getSalary() {
        return salary;
    }

    public void setSalary(String salary) {
        this.salary = salary;
    }

    public String getDept() {
        return dept;
    }

    public void setDept(String dept) {
        this.dept = dept;
    }
}

ConnectionPool.java

package sql;

import java.sql.*;

import static java.lang.System.out;

public class ConnectionPool {
    public static Connection getConn() {
        Connection conn = null;
        try {
            Class.forName("org.sqlite.JDBC");
            conn = DriverManager.getConnection(
                    "jdbc:sqlite:identifier.sqlite", "", ""
            );
            out.println("database connect success...");
        } catch (SQLException | ClassNotFoundException e) {
            e.printStackTrace();
        }
        return conn;
    }

    public static void close(Statement stmt, Connection conn) {
        try {
            if (stmt != null) {
                stmt.close();
                out.println("statement close...");
            }
            if (conn != null) {
                conn.close();
                out.println("connection close...");
            }
            out.println("database connect close...");
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void close(ResultSet rs, Statement stmt, Connection conn) {
        try {
            if (stmt != null) {
                rs.close();
                out.println("resultset close...");
            }
            if (rs != null) {
                stmt.close();
                out.println("statement close...");
            }
            if (conn != null) {
                conn.close();
                out.println("connection close...");
            }
            out.println("database connect close...");
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

EmployeeDao.java

package sql;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class EmployeeDao {
    private Connection conn;
    private PreparedStatement stmt;
    private ResultSet result;

    //对数据的添加
    public void insertEmployee(Employee emp){
        try {
            conn=ConnectionPool.getConn();
            stmt=conn.prepareStatement("insert into employee(emp_id,emp_name,job,salary,dept) values (?,?,?,?,?)");
            stmt.setString(1,emp.getEmpID());
            stmt.setString(2, emp.getEmpName());
            stmt.setString(3, emp.getJob());
            stmt.setString(4, emp.getSalary());
            stmt.setString(5, emp.getDept());
            int result=stmt.executeUpdate();
            if (result>=1){
                System.out.println("添加成功！");
            } else {
                System.out.println("添加失败！");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            ConnectionPool.close(stmt,conn);
        }
    }
    //对数据的修改
    public void modifyEmployee(Employee emp){
        try {
            conn=ConnectionPool.getConn();
            stmt=conn.prepareStatement("update employee set emp_name=?,job=?,salary=?,dept=? where emp_id=?");
            stmt.setString(1, emp.getEmpName());
            stmt.setString(2, emp.getJob());
            stmt.setString(3, emp.getSalary());
            stmt.setString(4, emp.getDept());
            stmt.setString(5,emp.getEmpID());
            int cout=stmt.executeUpdate();
            if (cout>=1){
                System.out.println("修改成功！");
            } else{
                System.out.println("修改失败！");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            ConnectionPool.close(stmt,conn);
        }
    }

    //对数据的删除
    public void deleteEmployeeById(String empId){
        try {
            conn=ConnectionPool.getConn();
            stmt=conn.prepareStatement("delete from employee where emp_id=?");
            stmt.setString(1,empId);
            int cout=stmt.executeUpdate();
            if (cout>=1){
                System.out.println("删除成功！");
            }else {
                System.out.println("删除失败！");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            ConnectionPool.close(stmt,conn);
        }

    }

    //对数据的查询
    public void queryEmpAll(){
        try {
            conn =ConnectionPool.getConn();
            stmt=conn.prepareStatement("select * from employee");
            result=stmt.executeQuery();
            System.out.println("员工编号：\t员工姓名：\t工作：  \t\t薪水：  \t\t部门编号：\t");
            while (result.next()){
                System.out.println(result.getString("EMP_ID")
                        +"\t\t\t"+ result.getString("EMP_NAME")
                        +"\t\t\t"+ result.getString("JOB")
                        +"\t\t"+ result.getString("SALARY")
                        +"\t\t"+ result.getString("DEPT"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            ConnectionPool.close(result,stmt,conn);
        }
    }
}

마지막으로 메인 함수를 생성하고 콘솔에서 실행해야 합니다.

메인.자바

package sql;

public class Main {
    public static void printInfo(String info){
        System.out.println("*******************************"+info+"************************************");
    }
    public static void main(String[] args) {
        EmployeeDao empDao=new EmployeeDao();
        Employee emp=new Employee();
        //查看原始信息
        printInfo("原始数据");
        empDao.queryEmpAll();
       // 添加信息
        printInfo("新增员工");
        emp.setEmpID("5");
        emp.setEmpName("张三");
        emp.setJob("clerk");
        emp.setSalary("9000");
        emp.setDept("20");
        empDao.insertEmployee(emp);
        empDao.queryEmpAll();
        //修改信息
        printInfo("修改编号为5的员工工资为1W");
        emp.setEmpID("5");
        //修改姓名
//        emp.setEmpName("张三");
        //修改工作
//        emp.setJob("clerk");
        //修改工资
        emp.setSalary("10000");
        //修改部门编号
//        emp.setDept("20");
        empDao.modifyEmployee(emp);
        empDao.queryEmpAll();
        //删除信息
        printInfo("删除编号为5的员工");
        empDao.deleteEmployeeById("5");
        empDao.queryEmpAll();
        
    }
}

콘솔에서 실행한 결과는 아래 그림과 같습니다. 

jdbc-3.36.0.3.jar" sql.Main
*******************************原始数据************************************
database connect success...
员工编号：	员工姓名：	工作：  		薪水：  		部门编号：	
1			王楠			男		22		10
2			张静			女		21		10
3			李刚			男		20		20
4			马明			男		23		20
resultset close...
statement close...
connection close...
database connect close...
*******************************新增员工************************************
database connect success...
添加成功！
statement close...
connection close...
database connect close...
database connect success...
员工编号：	员工姓名：	工作：  		薪水：  		部门编号：	
1			王楠			男		22		10
2			张静			女		21		10
3			李刚			男		20		20
4			马明			男		23		20
5			张三			clerk		9000		20
resultset close...
statement close...
connection close...
database connect close...
*******************************修改编号为5的员工工资为1W************************************
database connect success...
修改成功！
statement close...
connection close...
database connect close...
database connect success...
员工编号：	员工姓名：	工作：  		薪水：  		部门编号：	
1			王楠			男		22		10
2			张静			女		21		10
3			李刚			男		20		20
4			马明			男		23		20
5			张三			clerk		10000		20
resultset close...
statement close...
connection close...
database connect close...
*******************************删除编号为5的员工************************************
database connect success...
删除成功！
statement close...
connection close...
database connect close...
database connect success...
员工编号：	员工姓名：	工作：  		薪水：  		部门编号：	
1			王楠			男		22		10
2			张静			女		21		10
3			李刚			男		20		20
4			马明			男		23		20
resultset close...
statement close...
connection close...
database connect close...

进程已结束，退出代码为 0

배포된 서버(즉, 웹 페이지)에서 데이터베이스를 실행하려면, 

그런 다음 새 jsp 파일을 만들고 다음 코드를 입력하여 연결 가능 여부를 테스트한 다음 해당 데이터베이스 작업을 수행합니다.

<%@ page import="java.sql.*" %>
<%@ page import="javax.swing.*" %>
<%@ page import="sql.EmployeeDao" %>
<%@ page import="sql.Employee" %>
<%@ page import="sql.Main" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<%
    try{
        Class.forName("org.sqlite.JDBC");
        out.println("数据库驱动成功！");
        Connection conn= DriverManager.getConnection("jdbc:sqlite:C:/Users/lx/IdeaProjects/demo/identifier.sqlite");
        out.println("连接数据库成功！");
    }
    catch (SQLException e){
        e.printStackTrace();
        out.println("连接数据库失败！");
    }
    catch (ClassNotFoundException e){
        e.printStackTrace();
        JOptionPane.showMessageDialog(null, "加载数据库引擎失败");
    }
%>

</body>
</html>

~에

Connection conn= DriverManager.getConnection("jdbc:sqlite:C:/Users/lx/IdeaProjects/demo/identifier.sqlite");

경로는 identifier.sqlite의 절대 경로입니다.

 이 방법을 사용하면 아래 그림과 같은 연결 실패 문제가 계속 발생하며 아직 해결 방법을 찾지 못한 경우 추후 추가할 예정입니다.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 갱신

해결:

https://blog.csdn.net/m0_62404144/article/details/127482811