JAVA数据库基本操作,增删改查

package mypack;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.util.ArrayList;

public class DbOper {

// 查询多行记录

public ArrayList select() {

Connection conn = null;

PreparedStatement pstmt = null;

ResultSet rs = null;

ArrayList al = new ArrayList();

try {

conn = DbConn.getConn();

pstmt = conn.prepareStatement(“select * from titles”);

rs = pstmt.executeQuery();

while (rs.next()) {

Titles t = new Titles();

t.setTitleid(rs.getString(1));

t.setTitle(rs.getString(2));

al.add(t);

}

} catch (SQLException e) {

// TODO 自动生成 catch 块

e.printStackTrace();

} finally {

try {

if (rs != null) rs.close();

if (pstmt != null)pstmt.close();

if (conn != null)conn.close();

} catch (SQLException e) {

// TODO 自动生成 catch 块

e.printStackTrace();

}

}

return al;

}

//查询单个对象

public Titles selectOne(String titleid){

Connection conn = null;

PreparedStatement pstmt = null;

ResultSet rs = null;

Titles t = new Titles();

try {

conn = DbConn.getConn();

pstmt = conn.prepareStatement(“select * from titles where title_id=?”);

pstmt.setString(1,titleid);

rs = pstmt.executeQuery();

while (rs.next()) {

t.setTitleid(rs.getString(1));

t.setTitle(rs.getString(2));

}

} catch (SQLException e) {

// TODO 自动生成 catch 块

e.printStackTrace();

} finally {

try {

if (rs != null) rs.close();

if (pstmt != null)pstmt.close();

if (conn != null)conn.close();

} catch (SQLException e) {

// TODO 自动生成 catch 块

e.printStackTrace();

}

}

return t;

}

//增加记录

public boolean insert(Titles t){

Connection conn = null;

PreparedStatement pstmt=null;

boolean b = false;

try {

conn = DbConn.getConn();

pstmt = conn.prepareStatement(“insert into titles(title_id,title) values (?,?)”);

pstmt.setString(1,t.getTitleid());

pstmt.setString(2,t.getTitle());

int n = pstmt.executeUpdate();

if(n==1)

b=true;

} catch (SQLException e) {

// TODO 自动生成 catch 块

e.printStackTrace();

}finally{

try {

if(pstmt!=null)pstmt.close();

if(conn!=null)conn.close();

} catch (SQLException e) {

// TODO 自动生成 catch 块

e.printStackTrace();

}

}

return b;

}

//删除记录

public boolean delete(String titleid){

Connection conn = null;

PreparedStatement pstmt=null;

boolean b = false;

try {

conn = DbConn.getConn();

pstmt = conn.prepareStatement(“delete from titles where title_id=?”);

pstmt.setString(1,titleid);

int n = pstmt.executeUpdate();

if(n==1)

b=true;

} catch (SQLException e) {

// TODO 自动生成 catch 块

e.printStackTrace();

}finally{

try {

if(pstmt!=null)pstmt.close();

if(conn!=null)conn.close();

} catch (SQLException e) {

// TODO 自动生成 catch 块

e.printStackTrace();

}

}

return b;

}

//修改表

public boolean update(Titles t){

Connection conn = null;

PreparedStatement pstmt=null;

boolean b

= false;

try {

conn = DbConn.getConn();

pstmt = conn.prepareStatement(“update titles set title=? where title_id=?”);

pstmt.setString(1,t.getTitle());

pstmt.setString(2,t.getTitleid());

int n = pstmt.executeUpdate();

if(n==1)

b=true;

} catch (SQLException e) {

// TODO 自动生成 catch 块

e.printStackTrace();

}finally{

try {

if(pstmt!=null)pstmt.close();

if(conn!=null)conn.close();

} catch (SQLException e) {

// TODO 自动生成 catch 块

e.printStackTrace();

}

}

return b;

}

}