來源：ChuckMa 發(fā)布時間：2018-11-21 14:15:04 閱讀量：1092
這是數(shù)據(jù)庫增刪改查的Java代碼，隨即寫下來！Java部分的代碼全部在這里了
第一個實體類Emp
public class Emp {
private String empName;
private int empId;
public String getEmpName() {
return empName;
}
public void setEmpName(String empName) {
this.empName = empName;
}
public int getEmpId() {
return empId;
}
public void setEmpId(int empId) {
this.empId = empId;
}
}
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第二個類BaseDao(公共部分)，代碼如下:
public class BaseDao {
/**
*
* @param conn 連接對象
* @param sql sql 語句
* @param param 此數(shù)組，裝的是sql語句中的問題的替代數(shù)據(jù)
* @throws Exception
*/
public void exeSql(Connection conn, String sql, Object[] param)
throws Exception {
PreparedStatement pst = null;
pst = conn.prepareStatement(sql);
if (param != null) {
for (int i = 0; i < param.length; i++) {
pst.setObject(i + 1, param[i]);
}
}
pst.executeUpdate();
}
/**
* 得到查詢結(jié)果集
* @param conn
* @param sql
* @param param
* @return 返回結(jié)果集rs
* @throws Exception
*/
public ResultSet getRs(Connection conn, String sql, Object[] param)
throws Exception {
PreparedStatement pst = null;
pst = conn.prepareStatement(sql);
ResultSet rs = null;
if (param != null) {
for (int i = 0; i < param.length; i++) {
pst.setObject(i + 1, param[i]);
}
}
rs = pst.executeQuery();
return rs;
}
}
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第三個類EmpDao ，代碼如下:
public class EmpDao extends BaseDao{
/**
* 建表
* @param conn
* @throws Exception
*/
public void createTable(Connection conn)throws Exception{
String sql = "create table emp (empId tinyint primary key,empName varchar(20))";
Object [] param = null;
this.exeSql(conn,sql,param);//???
}
/**
* 數(shù)據(jù)添加
* @param conn
* @param emp
* @throws Exception
*/
public void addEmp(Connection conn,Emp emp) throws Exception{
String sql = "insert into emp(empId,empName) values(?,?)";
Object [] param = {emp.getEmpId(),emp.getEmpName()};
this.exeSql(conn,sql,param);
}
/**
* 數(shù)據(jù)刪除
* @param conn
* @param empId
* @throws Exception
*/
public void deleteEmpById(Connection conn,int empId)throws Exception{
String sql= "delete from emp where empId=?";
Object [] param = {empId};
this.exeSql(conn,sql,param);
}
/**
* 數(shù)據(jù)更新
* @param conn
* @param emp
* @throws Exception
*/
public void updateEmp(Connection conn,Emp emp)throws Exception{
String sql ="update emp set empName=? where empId=?";
Object []param ={emp.getEmpName(),emp.getEmpId()};
this.exeSql(conn,sql,param);
}
/**
* 數(shù)據(jù)查詢
* @param conn
* @return
* @throws Exception
*/
public ArrayList<Emp> findAllEmps(Connection conn)throws Exception{
String sql ="select *from emp";
Object [] param = null;
ResultSet rs = this.getRs(conn,sql,param);
ArrayList<Emp> empList = new ArrayList<Emp>();
while(rs.next()){
Emp emp = new Emp();
emp.setEmpId(rs.getInt("empId"));
emp.setEmpName(rs.getString("empName"));
empList.add(emp);
}
return empList;
}
}
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第四個類 工具類DbHelper ,代碼如下:
/**
* 連接和關(guān)閉
* @author Administrator
* static關(guān)鍵字，標(biāo)識為可以用類名直接調(diào)用類的屬性或方法。
*/
public class DbHelper {
public static Connection getConn()throws Exception{
Connection conn = null;
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mysql","root","1234567");
return conn;
}
public static void closeConn(Connection conn)throws Exception{
if(conn!=null){
conn.close();
}
}
}
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第五個類 Service 服務(wù)層，代碼如下:
public class EmpService {
/**
* 建表服務(wù)
*/
public void create() {
Connection conn = null;
try {
conn = DbHelper.getConn();
conn.setAutoCommit(false); //設(shè)置手動提交
EmpDao empDao = new EmpDao();
empDao.createTable(conn); //???
conn.commit(); //提交
DbHelper.closeConn(conn);
System.out.println("表創(chuàng)建成功");
} catch (Exception e) {
e.printStackTrace();
try {
conn.rollback();
} catch (SQLException e1) {
e1.printStackTrace();
}
}
}
/**
* 添加
* @param emp
*/
public void add(Emp emp) {
Connection conn = null;
try {
conn = DbHelper.getConn();
conn.setAutoCommit(false);
EmpDao empDao = new EmpDao();
empDao.addEmp(conn, emp);
conn.commit();
DbHelper.closeConn(conn);
System.out.println("數(shù)據(jù)添加成功");
} catch (Exception e) {
e.printStackTrace();
try {
conn.rollback();
} catch (SQLException e1) {
e1.printStackTrace();
}
}
}
/**
* 刪除
* @param empId
*/
public void delete(int empId) {
Connection conn = null;
try {
conn = DbHelper.getConn();
conn.setAutoCommit(false);
EmpDao empDao = new EmpDao();
empDao.deleteEmpById(conn, empId);
conn.commit();
DbHelper.closeConn(conn);
System.out.println("數(shù)據(jù)刪除成功");
} catch (Exception e) {
e.printStackTrace();
try {
conn.rollback();
} catch (SQLException e1) {
e1.printStackTrace();
}
}
}
/**
* 修改
* @param emp
*/
public void update(Emp emp) {
Connection conn = null;
try {
conn = DbHelper.getConn();
conn.setAutoCommit(false);
EmpDao empDao = new EmpDao();
empDao.updateEmp(conn, emp);
conn.commit();
DbHelper.closeConn(conn);
System.out.println("數(shù)據(jù)更新成功");
} catch (Exception e) {
e.printStackTrace();
try {
conn.rollback();
} catch (SQLException e1) {
e1.printStackTrace();
}
}
}
/**
* 查詢
* @return
*/
public ArrayList<Emp> findAllEmps() {
Connection conn = null;
ArrayList<Emp> empList = null;
try {
conn = DbHelper.getConn();
conn.setAutoCommit(false);
EmpDao empDao = new EmpDao();
empList = empDao.findAllEmps(conn);
conn.commit();
DbHelper.closeConn(conn);
System.out.println("數(shù)據(jù)查詢完畢!");
} catch (Exception e) {
e.printStackTrace();
try {
conn.rollback();
} catch (SQLException e1) {
e1.printStackTrace();
}
}
return empList;
}
}
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第六個類 測試類 Test ,代碼如下:
public class EmpTest {
public static void main(String[] args) {
Emp emp = new Emp();
emp.setEmpId(1);
emp.setEmpName("阿童木");
EmpService es = new EmpService();
// es.create(); //???
// es.add(emp);
// es.delete(66);
es.update(emp);
ArrayList<Emp> empList = es.findAllEmps();
for (int i = 0; i < empList.size(); i++) {
Emp emp2 = empList.get(i);
System.out.println("姓名:" + emp2.getEmpName() + " 序號:"
+ emp2.getEmpId());
}
}
}
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本次使用的數(shù)據(jù)庫是mysql數(shù)據(jù)庫！不足之處希望各位指出，我們共同學(xué)習(xí)，總結(jié)，進(jìn)步！
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