java之mysql数据库的链接及增删改查
Java中与数据库交互的步骤
1 新建一个工程
2 导包，在工程中导入连接MySQL数据库所使用的jar包
3 连接数据库
4 数据的增删改查
数据库的增删改查操作
步骤
1 获取刚刚创建的Connection对象
2 写sql语句
3 得到statement对象
4 执行sql语句，得到结果集
5 处理结果集
6 关闭资源
7 增加数据
DBUtil db = new DBUtil();
private Connection conn;
/*
插入数据
*/
@Override
public void insertUser(TeamWorker newUser) throws Exception {
Connection conn = db.getConn();
PreparedStatement pstm = null;
String sql_insert = "insert into teamworkerinfo(tb_pid,tb_pname,tb_ppsw) values(?,?,?)"; //sql语言
pstm = conn.prepareStatement(sql_insert);
//填充sql语句中的？
pstm.setString(1, newUser.getId());
pstm.setString(2, newUser.getName());
pstm.setString(3, newUser.getPwd());
//使用executeUpdate函数执行sql语句
int row = pstm.executeUpdate();
System.out.println("新增用户成功" + row + "行受到影响");
//释放对数据库的连接
db.closeConn(null, pstm, conn);
}
修改数据
DBUtil db = new DBUtil();
private Connection conn;
/*
从数据库中修改用户信息
*/
@Override
public void updateUser(String id, TeamWorker modUser) throws Exception {
Connection conn = db.getConn();
PreparedStatement pstm = null;
String sql_update = "update teamworkerinfo set tb_pname=?tb_ppsw=? where tb_pid=?";
pstm = conn.prepareStatement(sql_update);
pstm.setString(1,modUser.getName());
pstm.setString(2,modUser.getPwd());
pstm.setString(3,id);
int row = pstm.executeUpdate();
System.out.println("修改用户成功"+row+"行受到影响");
db.closeConn(null, pstm, conn);
}
删除数据
DBUtil db = new DBUtil();
private Connection conn;
/*
从数据表中删除用户信息
*/
@Override
public void deleteUser(String id) throws Exception {
Connection conn = db.getConn();
PreparedStatement pstm = null;
String sql_delete = "delete from teamworkerinfo where tb_pid=?";
pstm = conn.prepareStatement(sql_delete);
pstm.setString(1,id);
int row = pstm.executeUpdate();
System.out.println("删除用户成功"+row+"行受到影响");
db.closeConn(null, pstm, conn);
}
修改数据
DBUtil db = new DBUtil();
private Connection conn;
/*
从数据库中修改用户信息
*/
@Override
public void updateUser(String id, TeamWorker modUser) throws Exception {
Connection conn = db.getConn();
PreparedStatement pstm = null;
String sql_update = "update teamworkerinfo set tb_pname=?tb_ppsw=? where tb_pid=?";
pstm = conn.prepareStatement(sql_update);
pstm.setString(1,modUser.getName());
pstm.setString(2,modUser.getPwd());
pstm.setString(3,id);
int row = pstm.executeUpdate();
System.out.println("修改用户成功"+row+"行受到影响");
db.closeConn(null, pstm, conn);
}
