JDBC连接MYSQL数据库示例

JDBC是一种用于执行SQL语句的Java API，可以为多种关系数据库提供统一访问，它由一组用JAVA编写的类和接口组成。说白了就和PHP的PDO一样，通过JDBC，JAVA可以使用相同 的API接口来链接例如：MYSQL,SQLSERVER等不同类型的数据库。
连接mysql数据库：

package main;
http://www.kmnk03.com/hxpfk/dzpz/214.html
import java.sql.Connection;

import java.sql.DriverManager;
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public class Mysql {

public static void main(String arg[]) {

try {

Connection con = null; //定义一个MYSQL链接对象

Class.forName("com.mysql.jdbc.Driver").newInstance(); //MYSQL驱动

con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); //链接本地MYSQL

System.out.print("yes");

} catch (Exception e) {

System.out.print("MYSQL ERROR:" + e.getMessage());

}

}

}http://www.kmnk03.com/hxpfk/dzpz/217.html

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Class.forName("com.mysql.jdbc.Driver").newInstance(); 我们链接的是MYSQL数据库，所以需要一个MYSQL的数据库驱动，如果你的环境中木有安装，可以下载：mysql-connector-java-5.1.17-bin.jar
JAR包，然后放进jdk1.6.0_37\jre\lib\ext 重启eclispe 就可以在JRE系统库中看到。 
con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); 是链接数据库的语句，返回Connection con对象。参数格式：("jdbc:mysql://ip:端口/数据库名称",
用户名,密码) 
写入一条数据

package main;
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import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.Statement;
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public class Mysql {

/**

* 入口函数

* @param arg

*/

public static void main(String arg[]) {

try {http://www.kmnk03.com/hxpfk/bpy/220.html

Connection con = null; //定义一个MYSQL链接对象

Class.forName("com.mysql.jdbc.Driver").newInstance(); //MYSQL驱动

con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); //链接本地MYSQL

Statement stmt; //创建声明

stmt = con.createStatement();
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//新增一条数据

stmt.executeUpdate("INSERT INTO user (username, password) VALUES ('init', '123456')");

ResultSet res = stmt.executeQuery("select LAST_INSERT_ID()");

int ret_id;

if (res.next()) {

ret_id = res.getInt(1);

System.out.print(ret_id);

}http://www.kmnk03.com/hxpfk/xcy/223.html

} catch (Exception e) {

System.out.print("MYSQL ERROR:" + e.getMessage());

}http://www.kmnk03.com/hxpfk/bpy/222.html

}

}

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stmt.executeUpdate INSERT DELETE UPDATE语句都用executeUpdate函数来操作 
stmt.executeQuery SELECT语句都用stmt.executeQuery函数来操作 
ResultSet res = stmt.executeQuery("select LAST_INSERT_ID()"); 查询最后插入数据的ID号，返回ResultSet res对象 
删除和更新数据

package main;
http://www.kmnk01.com/hxpfk/2015/pz_1205/211.html
import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.Statement;

public class Mysql {
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/**

* 入口函数

* @param arg

*/

public static void main(String arg[]) {

try {

Connection con = null; //定义一个MYSQL链接对象

Class.forName("com.mysql.jdbc.Driver").newInstance(); //MYSQL驱动

con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); //链接本地MYSQL
http://www.kmnk01.com/hxpfk/2015/pz_1205/213.html
Statement stmt; //创建声明

stmt = con.createStatement();

//新增一条数据

stmt.executeUpdate("INSERT INTO user (username, password) VALUES ('init', '123456')");

ResultSet res = stmt.executeQuery("select LAST_INSERT_ID()");

int ret_id;

if (res.next()) {

ret_id = res.getInt(1);

System.out.print(ret_id);

}http://www.kmnk01.com/hxpfk/2015/pz_1205/214.html

//删除一条数据

String sql = "DELETE FROM user WHERE id = 1";

long deleteRes = stmt.executeUpdate(sql); //如果为0则没有进行删除操作，如果大于0，则记录删除的条数

System.out.print("DELETE:" + deleteRes);

//更新一条数据

String updateSql = "UPDATE user SET username = 'xxxx' WHERE id = 2";

long updateRes = stmt.executeUpdate(updateSql);

System.out.print("UPDATE:" + updateRes);

} catch (Exception e) {

System.out.print("MYSQL ERROR:" + e.getMessage());

}
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}

}

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删除和更新数据都使用stmt.executeUpdate函数。 
删除和更新数据都会返回一个Long的结果，如果为0，则删除或者更新失败，如果大于0则是操作的记录数 
查询语句

package main;
http://www.kmnk01.com/hxpfk/2015/bpy_1205/216.html
import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

import java.sql.Statement;

public class Mysql {

/**

* 入口函数

* @param arg

*/

public static void main(String arg[]) {

try {

Connection con = null; //定义一个MYSQL链接对象

Class.forName("com.mysql.jdbc.Driver").newInstance(); //MYSQL驱动

con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test", "root", "root"); //链接本地MYSQL
http://www.kmnk01.com/hxpfk/2015/bpy_1205/217.html
Statement stmt; //创建声明

stmt = con.createStatement();

//新增一条数据

stmt.executeUpdate("INSERT INTO user (username, password) VALUES ('init', '123456')");

ResultSet res = stmt.executeQuery("select LAST_INSERT_ID()");

int ret_id;

if (res.next()) {

ret_id = res.getInt(1);

System.out.print(ret_id);

}http://www.kmnk01.com/hxpfk/2015/bpy_1205/218.html

//删除一条数据

String sql = "DELETE FROM user WHERE id = 1";

long deleteRes = stmt.executeUpdate(sql); //如果为0则没有进行删除操作，如果大于0，则记录删除的条数

System.out.print("DELETE:" + deleteRes);

//更新一条数据

String updateSql = "UPDATE user SET username = 'xxxx' WHERE id = 2";

long updateRes = stmt.executeUpdate(updateSql);

System.out.print("UPDATE:" + updateRes);
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//查询数据并输出

String selectSql = "SELECT * FROM user";

ResultSet selectRes = stmt.executeQuery(selectSql);

while (selectRes.next()) { //循环输出结果集

String username = selectRes.getString("username");

String password = selectRes.getString("password");

System.out.print("\r\n\r\n");

System.out.print("username:" + username + "password:" + password);

}
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} catch (Exception e) {

System.out.print("MYSQL ERROR:" + e.getMessage());

}

kmnk03.com  kmnk01.com

}

}

www.kmnk03.com   www.kmnk01.com

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查询语句使用stmt.executeQuery函数 
rs.absolute() //绝对位置，负数表示从后面数 
rs.first()第一条 
rs.last()最后一条 
rs.previoust()前一条 
rs.next()后一条 
rs.beforeFirst()第一条之前 
rs.afterLast()最后之后 
rs.isFirst(),rs.isLast(),rs.isBeforeFirst(),rs.isAfterLast