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, "[email protected]", "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, "[email protected]", "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, "[email protected]", "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");
		}		
	}
}