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Home Backend Development PHP Tutorial php如何判断SQL语句的查询结果是否为空?

php如何判断SQL语句的查询结果是否为空?

Jun 23, 2016 pm 02:03 PM

代码如下:

$sql =mysql_query( "select * from tv_video where title like '%$keyword%' limit $offset,$PageSize");$result=mysql_fetch_array($sql);if(!empty($result)){while($result=mysql_fetch_array($sql)){echo "hello word!"}if(!empty($result)){echo "记录为空";}
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测试结果为:无论记录是否为空,都会输出"hello word!"与"记录为空",也就是两个条件都成立,这就让我很费解了,到底怎样判断一个SQL返回结果是否为空?


回复讨论(解决方案)

$result =mysql_query( "select * from tv_video where title like '%$keyword%' limit $offset,$PageSize");if (mysql_num_rows($result) < 1) echo '记录集为空';
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多谢前辈指点 ,小生刚学PHP 对很多函数不太了解。

$result =mysql_query( "select * from tv_video where title like '%$keyword%' limit $offset,$PageSize");if(count($result)<0){echo "查询无数据!";}
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这样试试

$result =mysql_query( "select * from tv_video where title like '%$keyword%' limit $offset,$PageSize");
if(!mysql_affected_rows()){
    echo '没有记录';
}

一楼的方法已经测试通过 ,三楼的估计应该不行,count值怎么也不会小于0吧,换成1应该也可以,四楼的mysql_affected_rows函数还真没见过,改天也测试下。

说明
int mysql_affected_rows ([ resource $link_identifier ] )
取得最近一次与 link_identifier 关联的 INSERT,UPDATE 或 DELETE 查询所影响的记录行数。 

多谢各位了,有问题再请教各位 。。

谢谢,对我有帮助

对我有帮助,不错,拿回去试试

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