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HomeBackend DevelopmentPHP Tutorial mysql_query() 的用法 怎样查询数据库中pic_url中的数据那解决办法

mysql_query() 的用法 怎样查询数据库中pic_url中的数据那
$con = mysql_connect ( "localhost", "root", "123" );
if (! $con) {
die ( 'could not connect' . mysql_error () );

}
mysql_select_db ( "zuoye", $con );
$st="select pic_url from user where username='" . $_SESSION ['id'] . "'";
$tu=mysql_query($st);
$r=mysql_fetch_array($tu);
print_r($r);
mysql_query() 返回的结果集是什么 是数组吗?


------解决方案--------------------
返回根据从结果集取得的行生成的数组,如果没有更多行则返回 FALSE。

mysql_fetch_array() 是 mysql_fetch_row() 的扩展版本。除了将数据以数字索引方式储存在数组中之外,还可以将数据作为关联索引储存,用字段名作为键名。

如果结果中的两个或以上的列具有相同字段名,最后一列将优先。要访问同名的其它列,必须用该列的数字索引或给该列起个别名。对有别名的列,不能再用原来的列名访问其内容(本例中的 'field')。 

php手册在手 打遍CSDN无敌手
------解决方案--------------------
mysql_query() 仅对 SELECT,SHOW,EXPLAIN 或 DESCRIBE 语句返回一个资源标识符,如果查询执行不正确则返回 FALSE。对于其它类型的 SQL 语句,mysql_query() 在执行成功时返回 TRUE,出错时返回 FALSE。

具体请看手册。
------解决方案--------------------
mysql_query返回的是一个指针或者一个bool啊
------解决方案--------------------
mysql_array()返回的是sql语句

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