Java - 數據操作 - JDBC
阿新 • • 發佈：2018-07-17
created private creat statement 圖片 驅動 display lex append 
實體類
1 import java.util.Date; 2 3 public class User { 4 private Integer id; 5 private String username; 6 private Integer sex; 7 private Integer age; 8 private Date createDate; 9 private Integer isDel; 10 public Integer getId() { 11 return id; 12 } 13View Codepublic void setId(Integer id) { 14 this.id = id; 15 } 16 public String getUsername() { 17 return username; 18 } 19 public void setUsername(String username) { 20 this.username = username; 21 } 22 public Integer getSex() { 23 return sex; 24 }25 public void setSex(Integer sex) { 26 this.sex = sex; 27 } 28 public Integer getAge() { 29 return age; 30 } 31 public void setAge(Integer age) { 32 this.age = age; 33 } 34 public Date getCreateDate() { 35 return createDate; 36 } 37 publicvoid setCreateDate(Date createDate) { 38 this.createDate = createDate; 39 } 40 public Integer getIsDel() { 41 return isDel; 42 } 43 public void setIsDel(Integer isDel) { 44 this.isDel = isDel; 45 } 46 @Override 47 public String toString() { 48 return "User [id=" + id + ", username=" + username + ", sex=" + sex + ", age=" + age + ", createDate=" 49 + createDate + ", isDel=" + isDel + "]"; 50 } 51 52 }
JDBC工具類 - 獲得連接
1 import java.sql.Connection; 2 import java.sql.DriverManager; 3 import java.sql.SQLException; 4 5 public class DBUtil { 6 7 private static final String URL = "jdbc:mysql:///imooc"; 8 private static final String USER = "root"; 9 private static final String PASSWORD = "root"; 10 11 private static Connection conn = null; 12 13 static { 14 try { 15 //1.加載驅動程序 16 Class.forName("com.mysql.jdbc.Driver"); 17 //2.獲得數據庫的連接 18 conn = DriverManager.getConnection(URL, USER, PASSWORD); 19 } catch (ClassNotFoundException e) { 20 e.printStackTrace(); 21 } catch (SQLException e) { 22 e.printStackTrace(); 23 } 24 } 25 26 public static Connection getConn(){ 27 return conn; 28 } 29 30 }View Code
數據持久類
1 import java.sql.Connection; 2 import java.sql.Date; 3 import java.sql.PreparedStatement; 4 import java.sql.ResultSet; 5 import java.sql.SQLException; 6 import java.util.ArrayList; 7 import java.util.List; 8 import java.util.Map; 9 10 import com.imooc.db.DBUtil; 11 import com.imooc.model.User; 12 13 public class UserDao { 14 15 public void addUser(User u) throws SQLException{ 16 Connection conn = DBUtil.getConn(); 17 String sql = "insert into user (user_name,sex,age,create_date,isdel) values(?,?,?,current_date(),?)"; 18 PreparedStatement ptmt = conn.prepareStatement(sql); 19 ptmt.setString(1, u.getUsername()); 20 ptmt.setInt(2, u.getSex()); 21 ptmt.setInt(3, u.getAge()); 22 ptmt.setInt(4, u.getIsDel()); 23 ptmt.execute(); 24 } 25 26 public void deleteUser(Integer id) throws SQLException{ 27 Connection conn = DBUtil.getConn(); 28 String sql = "delete from user where id=?"; 29 PreparedStatement ptmt = conn.prepareStatement(sql); 30 ptmt.setInt(1, id); 31 ptmt.execute(); 32 } 33 34 public void updateUser(User u) throws SQLException{ 35 Connection conn = DBUtil.getConn(); 36 String sql = "update user set user_name=?,sex=?,age=?,create_date=?,isdel=? where id=?"; 37 PreparedStatement ptmt = conn.prepareStatement(sql); 38 ptmt.setString(1, u.getUsername()); 39 ptmt.setInt(2, u.getSex()); 40 ptmt.setInt(3, u.getAge()); 41 ptmt.setDate(4, new Date(u.getCreateDate().getTime())); 42 ptmt.setInt(5, u.getIsDel()); 43 ptmt.setInt(6, u.getId()); 44 ptmt.execute(); 45 } 46 47 public List<User> conditionQuery(List<Map<String, Object>> params) throws SQLException{ 48 Connection conn = DBUtil.getConn(); 49 StringBuilder sb = new StringBuilder(); 50 sb.append("select * from user where 1=1 "); 51 if(params!=null && params.size()>0){ 52 for (Map<String, Object> param : params) { 53 sb.append("and "+param.get("field")+param.get("rela")+param.get("value")); 54 } 55 } 56 System.out.println(sb.toString()); 57 PreparedStatement ptmt = conn.prepareStatement(sb.toString()); 58 ResultSet rs = ptmt.executeQuery(); 59 60 List<User> users = new ArrayList<>(); 61 User u = null; 62 while(rs.next()){ 63 u = new User(); 64 u.setId(rs.getInt("id")); 65 u.setUsername(rs.getString("user_name")); 66 u.setSex(rs.getInt("sex")); 67 u.setAge(rs.getInt("age")); 68 u.setCreateDate(rs.getDate("create_date")); 69 u.setIsDel(rs.getInt("isdel")); 70 users.add(u); 71 } 72 return users; 73 } 74 75 public List<User> queryAll() throws SQLException{ 76 Connection conn = DBUtil.getConn(); 77 StringBuilder sb = new StringBuilder(); 78 sb.append("select * from user"); 79 PreparedStatement ptmt = conn.prepareStatement(sb.toString()); 80 ResultSet rs = ptmt.executeQuery(); 81 List<User> users = new ArrayList<>(); 82 User u = null; 83 while(rs.next()){ 84 u = new User(); 85 u.setId(rs.getInt("id")); 86 u.setUsername(rs.getString("user_name")); 87 u.setSex(rs.getInt("sex")); 88 u.setAge(rs.getInt("age")); 89 u.setCreateDate(rs.getDate("create_date")); 90 u.setIsDel(rs.getInt("isdel")); 91 users.add(u); 92 } 93 return users; 94 } 95 96 public User queryOne(Integer id) throws SQLException{ 97 Connection conn = DBUtil.getConn(); 98 StringBuilder sb = new StringBuilder(); 99 sb.append("select * from user where id=?"); 100 PreparedStatement ptmt = conn.prepareStatement(sb.toString()); 101 ptmt.setInt(1, id); 102 ResultSet rs = ptmt.executeQuery(); 103 User u = new User(); 104 u.setId(rs.getInt("id")); 105 u.setUsername(rs.getString("user_name")); 106 u.setSex(rs.getInt("sex")); 107 u.setAge(rs.getInt("age")); 108 u.setCreateDate(rs.getDate("create_date")); 109 u.setIsDel(rs.getInt("isdel")); 110 return u; 111 } 112 113 }View Code
控制類
1 import java.sql.SQLException; 2 import java.util.ArrayList; 3 import java.util.HashMap; 4 import java.util.List; 5 import java.util.Map; 6 7 import com.imooc.dao.UserDao; 8 import com.imooc.model.User; 9 10 public class Action { 11 12 private UserDao dao; 13 14 public void add(User u) throws SQLException { 15 dao = new UserDao(); 16 dao.addUser(u); 17 } 18 19 public void delete(Integer id) throws SQLException{ 20 dao = new UserDao(); 21 dao.deleteUser(id); 22 } 23 24 public void update(User u) throws SQLException{ 25 dao = new UserDao(); 26 dao.updateUser(u); 27 } 28 29 public void conditionQuery() throws SQLException{ 30 dao = new UserDao(); 31 List<Map<String, Object>> params = new ArrayList<>(); 32 Map<String, Object> param = new HashMap<>(); 33 param.put("field", "user_name"); 34 param.put("rela", "="); 35 param.put("value", "‘望望‘"); 36 params.add(param); 37 param.put("field", "id"); 38 param.put("rela", "="); 39 param.put("value", "‘2‘"); 40 params.add(param); 41 42 List<User> users = dao.conditionQuery(params); 43 for (User u : users) { 44 System.out.println(u); 45 } 46 } 47 48 public List<User> queryAll() throws SQLException{ 49 dao = new UserDao(); 50 return dao.queryAll(); 51 } 52 53 public User queryOne(Integer id) throws SQLException{ 54 dao = new UserDao(); 55 return dao.queryOne(id); 56 } 57 58 }View Code
Java - 數據操作 - JDBC