Java连接Mysql数据库增删改查操作

约定不等于承诺〃 2022-06-18 00:27 172阅读 0赞

//Java链接Mysql的类
    class operatedb
    {
      String driverName = "com.mysql.jdbc.Driver";  //加载JDBC驱动
      String dbURL = "jdbc:mysql://127.0.0.1:3306/student";  //要连接的服务器，数据库再此未指出
      Connection dbConn;
      Statement stmt;
      public  operatedb(String userName,String userPwd)//构造器的参数指明要连接的数据库、用户名和密码
       {
            try{
                Class.forName(driverName);
                dbConn = DriverManager.getConnection(dbURL, userName, userPwd);
            }catch (Exception e) {
                System.out.println("connection error!");
                e.printStackTrace();
            }
    	}
        
    	public void anyoperate(String sqls)
    	{
            try{
                stmt=dbConn.createStatement();
                stmt.execute(sqls);//将SLQ语句嵌入execute()方法中
                stmt.close() ; 
            }catch (Exception e) {
                System.out.println("anyoperate error!");
            }
    	}
        
    	public void insert(String sqls,String[] values)
    	{
            try{
                PreparedStatement prepare=dbConn.prepareStatement(sqls); 
                for(int i=0;i<values.length;i++)
                prepare.setString(i+1,values[i]);//指定values[0]为第一个参数，也就是代替sqls中的第一个“？”，values[1]为第二个参数，以此类推
                prepare.execute();
                prepare.close();
            }catch (Exception e) {
    			System.out.println(e);
            }
    	}
        
    	public void query(String sqls)
    	{
            try{
                stmt=dbConn.createStatement();
                ResultSet rset=stmt.executeQuery(sqls);
                while(rset.next())
                {
                     for(int i=1;i<=5;i++) {
                          
                         System.out.print(rset.getString(i)+"\t");
                    }
                     System.out.println(); 
                      
                }	
                rset.close() ;
                stmt.close() ; 
            }catch (Exception e) {
                System.out.println("query error!");
            }
    	  }
           public void closeconn()
           { 
                try{ 
                	dbConn.close();
                }catch (Exception e) {
                     System.out.println("close error!");
                }
            }
     }

//增删改查实例化操作
    //useoperatedb.java
    import java.io.*;
    import java.sql.*;
    public class useoperatedb
    {
        public static void main(String[] srg) throws IOException
        {
            String s1,s2;
            operatedb op1=new operatedb("root","123456");
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));	
            
            /*System.out.println("请输入要查询的专业:");
            s2=br.readLine();
            s1="select * from st1 where major='";
            s1=s1+s2+"'";
            op1.query(s1);*/
            
            System.out.println("添加一--------------");
            String[] v={"090811203","王五","女","90-05-05","信息"};
            s1="insert into st1 values(?,?,?,?,?)";
            op1.insert(s1,v);
            
            
            
            System.out.println("添加二--------------");
            String[] v1={"090811204","王六","男","90-06-06","计算机"};
            s1="insert into st1 values('"+v1[0]+"','"+v1[1]+"','"+v1[2]+"','"+v1[3]+"','"+v1[4]+"')";
            op1.anyoperate(s1);
            
                
            /*System.out.println("修改--------------");
            s1="update st1 set major='计算机' where major='computer'";
            op1.anyoperate(s1);*/
            
            System.out.println("删除--------------");
            s1="delete from st1  where major='计算机'";
            op1.anyoperate(s1);
             
            System.out.println("查询--------------");
            s1="select * from st1 ";
            op1.query(s1);
            
            op1.closeconn();
    	}	
    }