これはうまくいきます:
$updateSeats = mysql_query("UPDATE FORM_dateAndSeating
SET NumberOfSeats = '" . $removeSeatingNumber . "'
WHERE DATE = '" . $revertToStandardDate . "'");
長い形式:
$updateSeats = mysql_query("UPDATE FORM_dateAndSeating SET NumberOfSeats = '" . $removeSeatingNumber . "' WHERE DATE = '" . $revertToStandardDate . "'");
変数は、一重引用符を含む二重引用符で囲む必要があります
すなわち: '" . $removeSeatingNumber . "' WHERE DATE = '" . $revertToStandardDate . "'
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