Php 如何获取以前查找的行的MySQL主键？

$school\u ID\u result变量需要包含它刚刚查找的行的school\u ID（主键）（将只有一个）。

添加，然后从数组中获取

school\u ID

：

$query_check_domain_exists = "SELECT * FROM schools where domain ='$email_domain'";
$result_check_domain_exists = mysqli_query($d_schools, $query_check_domain_exists);
$school_ID_result = ?

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能否显示示例表数据和希望检索的示例？“SELECT*”返回包含主键字段的完整行。

$query_check_domain_exists = "SELECT * FROM schools where domain ='$email_domain'";
$result_check_domain_exists = mysqli_query($d_schools, $query_check_domain_exists);
$row = mysqli_fetch_assoc($result);
$school_ID_result = $row['school_ID'];