时间:2021-07-01 10:21:17 帮助过:11人阅读
1.java连接MySql数据库
代码区域:
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package com.oracle.jdbc.demo1;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class JDBCDemo {
//四个属性(四个常量的字符串)
/*
jdbcName
url
user
password
*/
private static final String jdbcName= "com.mysql.jdbc.Driver" ;
private static final String url= "jdbc:mysql://127.0.0.1:3306/emp_dept" ;
private static final String user= "root" ;
private static final String password= "123456" ;
/*
* 一个类(DriverManeger)四个接口(Connection、)
* */
public static void main(String[] args) {
// TODO Auto-generated method stub
Connection conn= null ;
try {
Class.forName(jdbcName);
conn=DriverManager.getConnection(url, user, password);
//获得conn就表示获取了数据库的连接
System.out.println( "连接数据库成功" );
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
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2.在java中向数据库添加数据
第一种方法:添加数据
代码区域:
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package com.oracle.jdbc.demo2;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
public class JDBCAdd {
private static final String jdbcName= "com.mysql.jdbc.Driver" ;
private static final String url= "jdbc:mysql://127.0.0.1:3306/emp_dept" ;
private static final String user= "root" ;
private static final String password= "123456" ;
/*
* 一个类(DriverManeger)四个接口(Connection、PreparedStatement、)
* */
public static void main(String[] args) {
// TODO Auto-generated method stub
Connection conn= null ;
try {
Class.forName(jdbcName);
conn=DriverManager.getConnection(url, user, password);
//增加数据的操作
String name= "田雨" ;
String sex= "女" ;
String sql= "insert into person values(null,‘" +name+ "‘,‘" +sex+ "‘)" ;
PreparedStatement pst=conn.prepareStatement(sql); //准备执行sql语句
int i=pst.executeUpdate(); //返回成功插入数据的行数
System.out.println( "成功添加了" +i+ "条记录" );
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
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第二中方法:添加数据
代码区域:
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package com.oracle.jdbc.demo2;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
public class JDBCAdd2 {
private static final String jdbcName= "com.mysql.jdbc.Driver" ;
private static final String url= "jdbc:mysql://127.0.0.1:3306/emp_dept" ;
private static final String user= "root" ;
private static final String password= "123456" ;
/*
* 一个类(DriverManeger)四个接口(Connection、PreparedStatement、)
* */
public static void main(String[] args) {
// TODO Auto-generated method stub
Connection conn= null ;
try {
Class.forName(jdbcName);
conn=DriverManager.getConnection(url, user, password);
//增加数据的操作
String name= "田雨2" ;
String sex= "女" ;
String sql= "insert into person values(null,?,?)" ;
PreparedStatement pst=conn.prepareStatement(sql); //准备执行sql语句
pst.setString( 1 , name); //填充第1个问好
pst.setString( 2 , sex); //填充第2个问好
int i=pst.executeUpdate(); //返回成功插入数据的行数
System.out.println( "成功添加了" +i+ "条记录" );
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
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3.在java中修改数据库的内容
代码区域:
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package com.oracle.jdbc.demo3;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
public class JDBCModify {
private static final String jdbcName= "com.mysql.jdbc.Driver" ;
private static final String url= "jdbc:mysql://127.0.0.1:3306/emp_dept" ;
private static final String user= "root" ;
private static final String password= "123456" ;
/*
* 一个类(DriverManeger)四个接口(Connection、PreparedStatement、)
* */
public static void main(String[] args) {
// TODO Auto-generated method stub
Connection conn= null ;
try {
Class.forName(jdbcName);
conn=DriverManager.getConnection(url, user, password);
//修改数据的操作
int id= 2 ;
String name= "王希宝" ;
String sex= "男" ;
String sql= "update person set name=?,sex=? where id=?" ;
PreparedStatement pst=conn.prepareStatement(sql); //准备执行sql语句
pst.setString( 1 , name); //填充第1个问好
pst.setString( 2 , sex); //填充第2个问好
pst.setInt( 3 , id);
int i=pst.executeUpdate(); //返回成功修改数据的行数
System.out.println( "成功修改了" +i+ "条记录" );
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
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4.在java中删除数据库的内容
代码区域:
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package com.oracle.jdbc.demo4;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
public class JDBCDel {
private static final String jdbcName= "com.mysql.jdbc.Driver" ;
private static final String url= "jdbc:mysql://127.0.0.1:3306/emp_dept" ;
private static final String user= "root" ;
private static final String password= "123456" ;
/*
* 一个类(DriverManeger)四个接口(Connection、PreparedStatement、)
* */
public static void main(String[] args) {
// TODO Auto-generated method stub
Connection conn= null ;
try {
Class.forName(jdbcName);
conn=DriverManager.getConnection(url, user, password);
//删除数据的操作
int id= 2 ;
String sql= "delete from person where id=?" ;
PreparedStatement pst=conn.prepareStatement(sql); //准备执行sql语句
pst.setInt( 1 , id);
int i=pst.executeUpdate(); //返回成功删除数据的行数
System.out.println( "成功删除了" +i+ "条记录" );
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
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5.在java中查看数据库的内容
代码区域:
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package com.oracle.jdbc.demo5;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class JDBCFindAll {
private static final String jdbcName= "com.mysql.jdbc.Driver" ;
private static final String url= "jdbc:mysql://127.0.0.1:3306/emp_dept" ;
private static final String user= "root" ;
private static final String password= "123456" ;
/*
* 一个类(DriverManeger)四个接口(Connection、PreparedStatement、ResultSet、)
* */
public static void main(String[] args) {
// TODO Auto-generated method stub
Connection conn= null ;
try {
Class.forName(jdbcName);
conn=DriverManager.getConnection(url, user, password);
//查询数据的操作
String sql= "select id,name,sex from person" ;
PreparedStatement pst=conn.prepareStatement(sql); //准备执行sql语句
ResultSet rs=pst.executeQuery();
while (rs.next()){
int id=rs.getInt( "id" );
String name=rs.getString( "name" );
String sex=rs.getString( "sex" );
System.out.println(id+ " " +name+ " " +sex);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
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在java中对数据库进行增删改查(转)
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