Rumah >pembangunan bahagian belakang >tutorial php >[PHP]更新中间关联表数据的两种思路,php思路_PHP教程
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@黑眼诗人
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中间关联表:这里的中间表只存表1的主键和表2的主键,即多对多的形式。
(执行数据添加和删除为框架内部方法,不属于思路部分)
<span>/*<br />|-----------------------------------------------------------<br />|方法一:先全部删除旧数据,后添加新数据<br />|@chenwei <www.chenwei.ws> |-----------------------------------------------------------<br />*/ </span><span>$res</span> = <span>$this</span>->classes->classEdit(<span>$id</span>, <span>$data</span>); <span>//</span><span>修改主表数据</span> <span>if</span>(<span>$res</span><span>) { </span><span>//</span><span>先删除关联表数据</span> <span>$bool</span> = <span>$this</span>->lesson_classes->lessonClassesDel(<span>$id</span><span>); </span><span>if</span>(<span>$bool</span><span>) {<br /> //循环组装条件,添加数据 </span><span>foreach</span>(<span>$lesson_ids</span> <span>as</span> <span>$val</span><span>)<br /> { </span><span>$arr</span> = <span>array</span>('class_id'=><span>$id</span>, 'lesson_id'=><span>$val</span><span>); //数据<br /> </span><span>$res</span> = <span>$this</span>->lesson_classes->lessonClassesAdd(<span>$arr</span><span>); //执行添加 } } </span><span> </span><span>$this</span>->show_tips('操作成功!'<span>); } </span><span>else</span><span> { </span><span>$this</span>->show_tips('操作失败!'<span>); }<br /><br />//弊端:大批量删除数据这块儿不安全,存在一定程度的安全隐患。<br /></span>
<span>/*<br />|---------------------------------------------------------<br />|方法二:只添加需要的,只删要删的<br />|@chenwei <www.chenwei.ws> |---------------------------------------------------------<br />*/ //库中查出的旧数据:</span><span>$arr_old</span><span> (处理过的一维数组) //提交过来的新数据:</span><span>$arr_new</span><span> (得到的一维数组) </span><span>$intersect</span> = <span>array_intersect</span>(<span>$arr_old</span>, <span>$arr_new</span>); <span>//</span><span>交集(需要保留的部分,不用处理)</span> <span>$result_del</span> = <span>array_diff</span>(<span>$arr_old</span>, <span>$intersect</span>); <span>//</span><span>旧数据中需要删除的</span> <span>$result_add</span> = <span>array_diff</span>(<span>$arr_new</span>, <span>$intersect</span>); <span>//</span><span>新数据中需要增加的 //添加新增数据</span> <span>if</span>(<span>$result_add</span> && <span>is_array</span>(<span>$result_add</span><span>)) { </span><span>foreach</span>(<span>$result_add</span> <span>as</span> <span>$val</span><span>) { </span><span>$data_add</span> = <span>array</span>('class_id'=><span>$id</span>, 'lesson_id'=><span>$val</span><span>); //数据 $bool_add = </span><span>$this</span>->lesson_classes->lessonClassesAdd(<span>$data_add</span><span>); //执行添加 } } </span><span>//</span><span>删除需要清除的数据</span> <span>if</span>(<span>$result_del</span> && <span>is_array</span>(<span>$result_del</span><span>)) { </span><span>foreach</span>(<span>$result_del</span> <span>as</span> <span>$val</span><span>) { </span><span>$bool_del</span> = <span>$this</span>->lesson_classes->lessonClassesDel(<span>$id</span>, <span>$val</span><span>); //执行删除 } }<br /><br />if($bool_add && $bool_del)<br />{<br /> $this->show_tips('操作成功!');<br />}<br />else<br />{<br /> $this->show_tips('操作失败!');<br />}<br /><br /><br />//特点:有针对性的添加数据和删除数据,较第一种方法,安全性高</span>
如果有不正确之处或更好的处理方式,请留言交流。
select `a`.*, `b`.`导师姓名` WHERE `a`.`导师ID` = `b`.`导师ID`
A表中导师ID为索引
B表中导师ID为主键
这样都不明白。。无奈了
你把你数据库里字段名写出来,别用文字代替了
另外还有要检索什么东西
直接写好sql给你就是了
if ($condition == ""){
$condition = "WHERE sid LIKE \"%".$id."%\"";
} else{
$condition .= "AND sid LIKE \"%".$id."%\"";
}
改成
condition = " AND sid LIKE \"%".$id."%\"";
然后SQL该下
$sql = 'select `data`.*, `teacher`.`tname` FROM `data`, `teacher` WHERE `data`.`tid` = `teacher`.`tid`' . $condition
就这样
delete from A where A.ID in (select B.ID from B where B.sum >100) 这只是一个例子 连表删除 还有连表查询 select * from a left join b on a.id=b.id where a.id=1 连表更新 update a,b set a.id=12 wehre b.id=2 没有经过测试啊