软件工程综合实践心得（1）
mysql 使用
- sql 文的使用（增、删、改、查询）
创建数据库 mybatis
a1. 表的创建 保存的表名 userinfo
|
userid |
int |
11 |
选中 |
||
|
username |
char |
20 |
|||
|
pwd |
char |
20 |
CREATE TABLE `userinfo` (
`userid` int(11) NOT NULL auto_increment,
`username` char(20) default NULL,
`pwd` char(20) default NULL,
PRIMARY KEY (`userid`)
)
INSERT INTO `userinfo` VALUES (1, ‘Zhang‘, ‘211‘);
INSERT INTO `userinfo` VALUES (2, ‘Li‘, ‘3243‘);
INSERT INTO `userinfo` VALUES (3, ‘Liu‘, ‘252‘);
INSERT INTO `userinfo` VALUES (4, ‘Quan‘, ‘894‘);
INSERT INTO `userinfo` VALUES (5, ‘Yan‘, ‘3251‘);
INSERT INTO `userinfo` VALUES (6, ‘Wu‘, ‘87589‘);
INSERT INTO `userinfo` VALUES (7, ‘Pi‘, ‘911‘);
A2.查询
Select * from userinfo where username = ‘Zhang’
package cn.neusoft.mybatis.jdbc;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class TestJdbc {
public static void main(String[] args) {
Connection con = null;
PreparedStatement ps = null;
ResultSet rs = null;
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection(
"jdbc:mysql://127.0.0.1:3306/mybatis?characterEncoding=utf-8",
"root",
"123");
String sql = "select * from userinfo where username = ?";
ps = con.prepareStatement(sql);?
ps.setString(1, "Zhang");
rs = ps.executeQuery();
while(rs.next()){
int userid = rs.getInt("userid");
String username = rs.getString("username");
String pwd = rs.getString("pwd");
System.out.println("编号:"+userid+"用户名:"+username+"密码"+
pwd);
}
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}