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//jdk6,7用法,创建接口
Page page = PageHelper.startPage(1, 10).setOrderBy("id desc").doSelectPage(new ISelect() {
@Override
public void doSelect() {
countryMapper.selectGroupBy();
}
});
//jdk8 lambda用法
Page page = PageHelper.startPage(1, 10).setOrderBy("id desc").doSelectPage(()-> countryMapper.selectGroupBy());
//为了说明可以链式使用,上面是单独setOrderBy("id desc"),也可以直接如下
Page page = PageHelper.startPage(1, 10, "id desc").doSelectPage(()-> countryMapper.selectGroupBy());
//也可以直接返回PageInfo,注意doSelectPageInfo方法和doSelectPage
pageInfo = PageHelper.startPage(1, 10).setOrderBy("id desc").doSelectPageInfo(new ISelect() {
@Override
public void doSelect() {
countryMapper.selectGroupBy();
}
});
//对应的lambda用法
pageInfo = PageHelper.startPage(1, 10).setOrderBy("id desc").doSelectPageInfo(() -> countryMapper.selectGroupBy());
//count查询,返回一个查询语句的count数
long total = PageHelper.count(new ISelect() {
@Override
public void doSelect() {
countryMapper.selectLike(country);
}
});
//lambda
total = PageHelper.count(()->countryMapper.selectLike(country)); |
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