Java中使用Statement接口SQL语句

Statement执行SQL语句：

1. 对数据库的曾删改操作时，使用stmt.executeUpdate(sql  执行给定 SQL 语句，分别为 insert 、update、delete.

2. 对数据库做查询时，直接使用 stmt.executeQuery(sql)，返回结果可以为一个resultSet结果集。

首先做一些准备工作：

①对要进行操作的数据库表进行封装，比如说我的数据mydata中的aistu表，用AiMember.java进行封装，以便后面操作。具体如下：

package com.mysqltest.jdbc.model;

/**
* 定义一个model
* 成员模型
* @author AI_STU
*
*/
public class AiMember {

private String name;
private int id;
private int age;
private String email;
private String tel;
private double salary;
private String riqi;

/**
* alt+shift+s 添加构造函数generating constructor using fields.
* @param name
* @param id
* @param age
* @param email
* @param tel
* @param salary
* @param riqi
*/
public AiMember(String name, int id, int age, String email, String tel, double salary, String riqi) {
super();
this.name = name;
this.id = id;
this.age = age;
this.email = email;
this.tel = tel;
this.salary = salary;
this.riqi = riqi;
}

//重构
public AiMember(int id) {
super();
this.id = id;
}

public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getTel() {
return tel;
}
public void setTel(String tel) {
this.tel = tel;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public String getRiqi() {
return riqi;
}
public void setRiqi(String riqi) {
this.riqi = riqi;
}

}

②对连接MySQL数据库，和关闭连接方法进行封装，这里用DbUtil.java进行封装，具体如下：

package com.mysqltest.jdbc.modelComp;

public class CompMember {

private int id;
private String name;
private int age;
private double salary;

/**
* 构造函数1
* @param name
* @param age
* @param salary
*/
public CompMember(String name, int age, double salary) {
super();
this.name = name;
this.age = age;
this.salary = salary;
}

/**
* 重载构造函数
* @param id
* @param name
* @param age
* @param salary
*/
public CompMember(int id, String name, int age, double salary) {
super();
this.id = id;
this.name = name;
this.age = age;
this.salary = salary;
}

/**
* get,set方法
*/
public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}

public double getSalary() {
return salary;
}

public void setSalary(double salary) {
this.salary = salary;
}

@Override
/**
* 改写toString,使得显示更好
*/
public String toString() {
return "["+this.id+"]"+this.name+","+this.age+","+this.salary;
}
}

准备工作做好了，下面开始使用Statement接口执行sql语句来实现增删改：

①增：

package com.mysqltest.jdbc.two2;

import java.sql.Connection;
import java.sql.Statement;

import com.mysqltest.jdbc.model.AiMember;
import com.mysqltest.jdbc.util.DbUtil;

public class Demo3 {

/**
* 添加成员到表中1
* @param name
* @param id
* @param age
* @param email
* @param tel
* @param salary
* @param riqi
* @return
* @throws Exception
*/
@SuppressWarnings("unused")
private static int addMember(String name,int id,int age,String email,String tel,double salary,String riqi) throws Exception{

DbUtil dbUtil = new DbUtil();//之前封装好的
Connection con = dbUtil.getCon(); //获取数据库连接
String sql = "insert into aistu values('"+name+"',"+id+",'"+age+"','"+email+"','"+tel+"','"+salary+"','"+riqi+"')";
Statement stmt = con.createStatement();//获取statement
int result = stmt.executeUpdate(sql);
dbUtil.close(stmt, con);
return result;
}

/**
* 添加成员到表中2方法
* @param mem
* @return
* @throws Exception
*/
private static int addMember2(AiMember mem) throws Exception{ //AiMember也是之前封装好的
// mem.getName();
DbUtil dbUtil = new DbUtil();//之前封装好的
Connection con = dbUtil.getCon(); //获取数据库连接
String sql = "insert into aistu values('"+mem.getName()+"',"+mem.getId()+",'"+mem.getAge()+"','"+mem.getEmail()+"','"+mem.getTel()+"','"+mem.getSalary()+"','"+mem.getRiqi()+"')";
Statement stmt = con.createStatement();//获取statement
int result = stmt.executeUpdate(sql);
dbUtil.close(stmt, con);
return result;
}

// private static int addMenber2()

public static void main(String[] args) throws Exception {

/*int result = addMember("刘翔", 4, 28, "15xliu@stu.edu.cn", "13411957776", 8000.00, "2015-09-10");
if(result==1){
System.out.println("添加成功");
}else{
System.out.println("添加失败");
}*/ //多行注释，ctrl+shift+/

AiMember mem = new AiMember("李娜", 6, 25, "15nli@stu.edu.cn", "13411957775", 8000.00, "2015-09-03");
int result = addMember2(mem);
if(result==1){
System.out.println("添加成功");
}else{
System.out.println("添加失败");
}
}
}


②改：

package com.mysqltest.jdbc.two3;

import java.sql.Connection;
import java.sql.Statement;

import com.mysqltest.jdbc.model.AiMember;
import com.mysqltest.jdbc.util.DbUtil;

public class Demo4 {

private static DbUtil dbUtil = new DbUtil();

// @SuppressWarnings("unused")
/**
* 修改成员
* @param mem
* @return
* @throws Exception
*/
private static int updateMember(AiMember mem) throws Exception {

Connection con = dbUtil.getCon(); // 获取数据库连接
String sql = "update aistu set name='" + mem.getName() + "',id=" + mem.getId() + ",age='" + mem.getAge()
+ "',email='" + mem.getEmail() + "',tel='" + mem.getTel() + "',salary='" + mem.getSalary() + "',riqi='"
+ mem.getRiqi() + "' where id=" + mem.getId();
//格式化，ctrl+a全选，然后ctrl+shift+f格式化
Statement stmt = con.createStatement();// 获取statement
int result = stmt.executeUpdate(sql);
dbUtil.close(stmt, con);
return result;
// return 0;
}

public static void main(String[] args) throws Exception {
AiMember mem = new AiMember("劳尔", 6, 24, "14elao@stu.edu.cn", "13411957770", 18000.00, "2014-09-03");
int result = updateMember(mem);
if (result==1) {
System.out.println("更新成功");
} else {
System.out.println("更新失败");
}
}
}

③删：

package com.mysqltest.jdbc.two4;

import java.sql.Connection;
import java.sql.Statement;

import com.mysqltest.jdbc.model.AiMember;
import com.mysqltest.jdbc.util.DbUtil;

public class Demo5 {

private static DbUtil dbUtil = new DbUtil();

public static int deletMember(AiMember mem) throws Exception{

Connection con = dbUtil.getCon(); // 获取数据库连接
String sql = "delete from aistu where id="+mem.getId();
Statement stmt = con.createStatement();// 获取statement
int result = stmt.executeUpdate(sql);
dbUtil.close(stmt, con);
return result;
}

public static void main(String[] args) throws Exception {
AiMember mem = new AiMember(5);
int result = deletMember(mem);
if (result==1) {
System.out.println("成功删除成员");

} else {
System.out.println("删除成员失败");
}
}
}