JDBC连接MYSQL数据库的代码

最新推荐文章于 2023-02-14 09:11:04 发布

原创最新推荐文章于 2023-02-14 09:11:04 发布 · 417 阅读

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CC 4.0 BY-SA版权

文章标签：

#jdbc连接 #mysql数据库

本文详细介绍了使用JDBC连接MySQL数据库的方法，包括插入、查询、更新和删除数据的具体实现。通过示例代码展示了如何执行SQL语句，获取并处理查询结果。

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下边代码段是关于JDBC连接MYSQL数据库的代码。

package main;

import java.sql.Connection;
import java.sql.DriverManager;

public class Mysql {
	public static void main(String arg[]) {
		try {
			System.out.print("yes");
		} catch (Exception e) {
			System.out.print("MYSQL ERROR:" + e.getMessage());
		}
		
	}
}


                                
                        
                                
                                
                        
                                

package main;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class Mysql {
	
	public static void main(String arg[]) {
		try {
			
			stmt = con.createStatement();
			
			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);
			}
			
			
			
		} catch (Exception e) {
			System.out.print("MYSQL ERROR:" + e.getMessage());
		}
		
	}
}

stmt.executeUpdateINSERTDELETEUPDATE语句都用executeUpdate函数来操作stmt.executeQuerySELECT语句都用stmt.executeQuery函数来操作ResultSetres=stmt.executeQuery(“selectLAST_INSERT_ID()”);查询最后插入数据的ID号，返回ResultSetres对象删除和更新数据

package main;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class Mysql {
	
	public static void main(String arg[]) {
		try {
			
			stmt = con.createStatement();
			
			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);
			}
			
			String sql = "DELETE FROM user WHERE id = 1";
			System.out.print("DELETE:" + deleteRes);
			
			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());
		}
		
	}
}

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;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;

public class Mysql {
	
	public static void main(String arg[]) {
		try {
			
			stmt = con.createStatement();
			
			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);
			}
			
			String sql = "DELETE FROM user WHERE id = 1";
			System.out.print("DELETE:" + deleteRes);
			
			String updateSql = "UPDATE user SET username = 'xxxx' WHERE id = 2";
			long updateRes = stmt.executeUpdate(updateSql);
			System.out.print("UPDATE:" + updateRes);
			
			ResultSet selectRes = stmt.executeQuery(selectSql);
				String username = selectRes.getString("username");
				String password = selectRes.getString("password");
				System.out.print("rnrn");
				System.out.print("username:" + username + "password:" + password);
			}
			
			
		} catch (Exception e) {
			System.out.print("MYSQL ERROR:" + e.getMessage());
		}
		
	}
}