mysqli php

Question

这让我兴奋。

mb_detect_order("UTF-8");
$str_firstName = ucwords(strtolower(trim($str_firstName)));
$str_encoding = mb_detect_encoding($str_firstName);
$str_firstName = mb_convert_encoding($str_firstName, "UTF-8", mb_detect_encoding($str_firstName));
$str_sql="SELECT * FROM db6901371_clients.costCentreClients cCC WHERE isDeleted = 0 AND cCC.firstName = '$str_firstName'";
echo "<br>str_sql= ".$str_sql."</br>";//works when cut and pasted into phoMyAdmin
$res = $mysqli->query($str_sql) or die("Line ".__LINE__.$mysqli->error);
$res->num_rows;
$res->data_seek(0);
$row = $res->fetch_assoc();
if ($res->num_rows>0) {
   //firstName exists
   }

从文本文件中读入

$str_firstName 如果剪切并粘贴到phpMyAdmin中，$str_sql将找到记录，但从php运行时则不会。 我在sql中尝试了LIKE，BINARY和各种COLLATE语句。 在文本文件中并且在db6901371_clients.costCentreClients中具有匹配项的30多个名称中，只返回1的匹配项。