实现批量删除和模糊查询

实现批量删除和模糊查询

1、实现批量删除：

package test_path;

import org.junit.Test;

import java.sql.*;

public class MoHuAndDeleteTest {

    @Test
    public void testMoMu(){
        Connection conn=null;
        PreparedStatement ps=null;
        ResultSet rs=null;
        String mohu="a";
        try{
            //1、注册驱动
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test1", "root", "root");
            ps=conn.prepareStatement("select * from t_user where uname like concat('%',?,'%')");
            ps.setObject(1,mohu);
            rs = ps.executeQuery();
            while (rs.next()){
                System.out.println(rs.getInt(1)+","+rs.getString(2)+","+rs.getString(3));
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            if(rs!=null){
                try {
                    rs.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }

    }
}

2、实现模糊查询：

package test_path;

import org.junit.Test;

import java.sql.*;

public class MoHuAndDeleteTest {

    @Test
    public void testMoMu(){
        Connection conn=null;
        PreparedStatement ps=null;
        ResultSet rs=null;
        String ids="1,2,3";
        try{
            //1、注册驱动
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test1", "root", "root");
            ps=conn.prepareStatement("delete from t_user where id in(?)");
            ps.setObject(1,ids);
            int i = ps.executeUpdate();
            System.out.println("结果："+i);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            if(rs!=null){
                try {
                    rs.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }

    }
}

可以达到删除效果，但是永远删除的是第一行数据

总结：

模糊查询，批量删除里面不能用占位符