sql语句查询

xxxImpl.java  继承 IDao<xxx>

以qqUser为例

public class qqDaoImpl implements IDao<qqUser> {
    @Override
    public int insert(qqUser qqUser) throws SQLException {
        String sql="insert into qqUser values(?,?,?)";
        return jdbcUtils.update(sql,qqUser.getId(),qqUser.getPassword(),qqUser.getName()) ;
    }
//在方法体内部根据形参EmpBean中的某些属性是否为空来动态拼接SQL语句，处理不同的查询需求
    @Override
    public ArrayList<qqUser> queryData(qqUser qqUser) throws SQLException {
        String sql="select * from qqUser where 1=1 ";
        ArrayList<Object> whereValues=new ArrayList<>();
        if(qqUser!=null){
            if(qqUser.getId()!=null){
                sql+="and id=?";
                whereValues.add(qqUser.getId());
            }
        }
        ArrayList<qqUser> qqUserArrayList=jdbcUtils.queryDate(sql, new rowmapper<day2.bean.qqUser>() {
            @Override
            public qqUser rowMap(ResultSet rs) throws SQLException {
                qqUser qqUser1 = new qqUser();
                qqUser1.setId(rs.getString("id"));
                qqUser1.setName(rs.getString("name"));
                qqUser1.setPassword(rs.getString("password"));
                return qqUser1;
            }
        },whereValues.toArray());
        return qqUserArrayList;
    }
}

　　测试类

qqDaoImpl qqDao = new qqDaoImpl();
        ArrayList<qqUser> qqUserArrayList=null;

        //插入用户
//        qqUser qqUser2 = new qqUser("12780","1232","hello7");
//        qqDao.insert(qqUser2);
        
        qqUser qqUser = new qqUser();
        qqUser.setId("12784");
        qqUserArrayList=qqDao.queryData(qqUser);
        for(qqUser s:qqUserArrayList){
            System.out.println(s);
        }

标签：语句,qqUser,ArrayList,查询,qqUserArrayList,sql,new,qqUser1
来源： https://www.cnblogs.com/lyl890/p/16592728.html