MYSQL：選擇其中的/和/或帶有兩個表

Question

我正在嘗試使以下SQl工作：

SELECT * FROM tc_appointment as tcAppointment, tc_message as tcMessage
WHERE tcAppointment.counsellor_id = 502
AND 
(
    (tcAppointment.tc_message_id = tcMessage.id AND tcMessage.marked_read = false AND tcMessage.sender_id != 502)
    OR
    (tcAppointment.cancelled = true AND tcAppointment.cancelled_acknowledged = false)
    OR 
    (tcAppointment.confirmed = false)
);

在表中唯一的tc_appointment條目中， tcAppointment.tc_message_id為null。 我正在嘗試讓它返回，因為counsellor_id = 502並且第二個OR語句為true

由於tc_message as tcMessage子句和第一個AND / OR語句，我似乎被卡住了，但是我不確定為什么。 誰能指出我正確的方向？

Answer 1

嘗試聯接2個表並使用“位置”：

 SELECT * FROM tc_appointment as tcAppointment 
    LEFT JOIN tc_message as tcMessage 
    ON 
    ((tcAppointment.tc_message_id = tcMessage.id AND tcMessage.marked_read = false AND tcMessage.sender_id != 502)
    OR
        (tcAppointment.cancelled = true AND tcAppointment.cancelled_acknowledged = false)
        OR 
        (tcAppointment.confirmed = false)
) 

    WHERE tcAppointment.counsellor_id = 502