Mysql连接数据库

Posted 2022-01-28 小魁的C世界

1.获取数据库连接 

package com.shop.Dbcon;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DBConnction 
	static final String DRIVERNAME="com.mysql.jdbc.Driver";
	static final String URL="jdbc:mysql://localhost:3306/shopingdb?useSSL=false";
	static final String NAME="root";
	static final String PASSWORD="020823";
	//加载驱动
	static 
		try 
			Class.forName(DRIVERNAME);
		 catch (ClassNotFoundException e) 
			// TODO Auto-generated catch block
			e.printStackTrace();
		
	
	//获取数据库连接
	public static Connection getCon()
		Connection conn=null;
		try 
			conn=DriverManager.getConnection(URL, NAME, PASSWORD);
		 catch (SQLException e) 
			// TODO Auto-generated catch block
			e.printStackTrace();
		
		return conn;
		
	
	public static void close(ResultSet rs,PreparedStatement ps,Connection conn) 
		try 
			if (rs!=null) 
				rs.close();
			
			if (ps!=null) 
				ps.close();
			
			if (conn!=null) 
				conn.close();
			
		 catch (SQLException e) 
			// TODO Auto-generated catch block
			e.printStackTrace();
		
	
	public static void main(String[] args) 
		DBConnction conn=new DBConnction();
		System.out.println(conn);

	

2.增删改查操作

package com.win;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.mysql.jdbc.Connection;
import com.sql.DbConnection;

public class BASEDAO 
	static Connection conn=null;
	static java.sql.PreparedStatement ps=null;
	static ResultSet rs=null;
	
	public static String[][] getTableData()
		List<Emp> emplist=new ArrayList<Emp>();
		try 
			String sql="select * from tb_book";
			conn=DbConnection.getcon();
			ps=conn.prepareStatement(sql);
			rs=ps.executeQuery();
			while (rs.next()) 
				Emp emp=new Emp();
				emp.setId(rs.getString("id"));
				emp.setBookName(rs.getString("bookName"));
				emp.setAuthor(rs.getString("author"));
				emp.setSex(rs.getString("sex"));
				emp.setPrice(rs.getString("price"));
				emp.setBookDesc(rs.getString("bookDesc"));
				emplist.add(emp);
			
		 catch (SQLException e) 
			e.printStackTrace();
		
		String[][] dataStrings=new String[emplist.size()][6];
		for (int i = 0; i < dataStrings.length; i++) 
			dataStrings[i]=emplist.get(i).toArray();
		
		return dataStrings;
	

	public static void main(String[] args) 
		BASEDAO dao=new BASEDAO();
		String[][] result=dao.getTableData();
		System.out.println(result);
	
	public static boolean onAdd(Emp emp)
		try 
			String sql="insert into tb_book value(?,?,?,?,?,?)";
			conn=DbConnection.getcon();
			ps=conn.prepareStatement(sql);
			ps.setString(1, emp.getId());
			ps.setString(2, emp.getBookName());
			ps.setString(3, emp.getAuthor());
			ps.setString(4, emp.getSex());
			ps.setString(5, emp.getPrice());
			ps.setString(6, emp.getBookDesc());
			return ps.executeUpdate()>0;
			
		 catch (SQLException e) 
			e.printStackTrace();
		
		return false;

	

	public boolean deleteData(Emp emp) 
		try 
			String sql="delete from tb_book where id=?";
			conn=DbConnection.getcon();
			ps=conn.prepareStatement(sql);
			ps.setString(1, emp.getId());
			return ps.executeUpdate()>0;
		 catch (SQLException e) 
			e.printStackTrace();
		
		return false;
	

	public String[][] findData(Object bookName) 
		List<Emp> emplist=new ArrayList<Emp>();
		try 
			String sql="select * from tb_book where bookName like '%"+bookName+"%'";
			conn=DbConnection.getcon();
			ps=conn.prepareStatement(sql);
			rs=ps.executeQuery();
			while (rs.next()) 
				Emp emp=new Emp();
				emp.setId(rs.getString("id"));
				emp.setBookName(rs.getString("bookName"));
				emp.setAuthor(rs.getString("author"));
				emp.setSex(rs.getString("sex"));
				emp.setPrice(rs.getString("price"));
				emp.setBookDesc(rs.getString("bookDesc"));
				emplist.add(emp);
			
		 catch (SQLException e) 
			e.printStackTrace();
		
		String[][] dataStrings=new String[emplist.size()][6];
		for (int i = 0; i < dataStrings.length; i++) 
			dataStrings[i]=emplist.get(i).toArray();
		
		return dataStrings;
	
	

3.获取数据库内容

package com.book.bean;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class TitleDao2 
	static Connection conn = null;// 连接接口
	static PreparedStatement ps = null;// 执行语句接口
	static ResultSet rs = null;// 结果集接口
	// 查询结果集方法

	public static String[][] getTableData() 
		List<TitleEntity> empList = new ArrayList<TitleEntity>();
		try 
			String sql = "select * from tb_book";
			conn = DbConnction.getConnction();
			ps = conn.prepareStatement(sql);
			rs = ps.executeQuery();
			while (rs.next()) 
				TitleEntity tey = new TitleEntity();
				tey.setIsbn(rs.getString("isbn"));
				tey.setTitle(rs.getString("title"));
				tey.setEditionNumber(rs.getString("editionNumber"));
				tey.setCopyright(rs.getString("copyright"));
				tey.setPublisherId(rs.getString("publisherID"));
				tey.setCopyTime(rs.getString("imageFile"));
				tey.setPrice(rs.getString("price"));
				empList.add(tey);
			
		 catch (SQLException e) 
			e.printStackTrace();
		
		String[][] dataStrings = new String[empList.size()][4];
		for (int i = 0; i < dataStrings.length; i++) 
			dataStrings[i] = empList.get(i).toArray();
		
		return dataStrings;
	

<%@page import="com.book.bean.TitleDao2"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<%@page import="java.sql.*"%>
<jsp:useBean id="dbcon" class="com.book.bean.DbConnction" scope="request" />
<jsp:useBean id="es" class="com.book.bean.TitleDao2" scope="request" />
<html>
<head>
<title>获取书本页面</title>
</head>
<body>
	<table border="1">
		<tr bgcolor="gray">
			<td>ISBN</td>
			<td>title</td>
			<td>copyright</td>
			<td>copyTime</td>
			<td>editionNumber</td>
			<td>publisherId</td>
			<td>price</td>
		</tr>
		<%
		Connection dbCon = dbcon.getConnction();
		Statement stmt = dbCon.createStatement();
		ResultSet rs = stmt.executeQuery("select * from tb_book");
		while (rs.next()) 
		%>
		<tr>
			<td><%=rs.getString("isbn")%></td>
			<td><%=rs.getString("title")%></td>
			<td><%=rs.getString("copyright")%></td>
			<td><%=rs.getString("editionNumber")%></td>
			<td><%=rs.getString("copyTime")%></td>
			<td><%=rs.getString("publisherId")%></td>
			<td><%=rs.getString("price")%></td>
		</tr>
		<%
		
		%>
	</table>
</body>
</html>

转换方法：
public String[] toArray() 
		String[] dataStrings = new String[7];
		dataStrings[0] = isbn;
		dataStrings[1] = title;
		dataStrings[2] = copyright;
		dataStrings[3] = copyTime;
		dataStrings[4] = String.valueOf(editionNumber);
		dataStrings[5] = String.valueOf(publisherId);
		dataStrings[6] = String.valueOf(price);
		return dataStrings;