$sql = "select * from tb_user where name=' ".$_GET['user']." ' "; 整条语句是这样的 我就是搞不懂为什么要加上两个”.“ 在mysql查询中无缘无故带上两个”.“
$sql = "select * from tb_user where name=' ".$_GET['user']." ' "; 在这个语句中.在外面所以替换完类似如下(假如$_GET['user']为zhangsan): $sql = "select * from tb_user where name='zhangsan';
$sql = "select * from tb_user where name='zhangsan'";
"select ...." 这个字符串是不能直接和$_GET['user']连接的 中间必须使用连接符" . " 这样才能使用 假设$_GET['user']为"zhangshan" 那么这一句就是 $sql = "select * from tb_user where name='zhangshan' ";
哦 好像有点懂了 那我把它去掉 $sql = "select * from tb_user where name=' "$_GET['user']" ' "; (假如$_GET['user']为zhangsan): 也表示$sql = "select * from tb_user where name='zhangsan'”;吗?
$sql = "select * from tb_user where name='\"{$_GET['user']}\"'";
顶楼上的 也能这样写 $sql = "select * from tb_user where name='{$_GET['user']}'";
或者写成$sql = "select * from tb_user where name=' ."$_GET['user']". ' "; 能表达链接的意思吗?
或者 $user = $_GET['user']; $sql = "select * from tb_user where name='$user'";
$sql = "select * from tb_user where name=' "$_GET['user']" ' ";这个不对."."是连字符. 你这句话等于是三个字符串. "select * from tb_user where name=' " $_GET['user'] " ' "得用连字符把他们连接起来才行.
$user = ".zhangsan.";(加入$_GET['user']为zhangsan),变量是要带$的
在这个语句中.在外面所以替换完类似如下(假如$_GET['user']为zhangsan):
$sql = "select * from tb_user where name='zhangsan';
假设$_GET['user']为"zhangshan" 那么这一句就是
$sql = "select * from tb_user where name='zhangshan' ";
(假如$_GET['user']为zhangsan):
也表示$sql = "select * from tb_user where name='zhangsan'”;吗?
$sql = "select * from tb_user where name='{$_GET['user']}'";
$user = $_GET['user'];
$sql = "select * from tb_user where name='$user'";
$sql = "select * from tb_user where name=' "$_GET['user']" ' ";这个不对."."是连字符.
你这句话等于是三个字符串.
"select * from tb_user where name=' "
$_GET['user']
" ' "得用连字符把他们连接起来才行.