Php 使用大小写时，操作数应包含1列sql

当我尝试运行此查询时，它会显示错误为“操作数应包含1列”。请帮助我。当我使用CASE时，当o.ship\u address=0，则（a.entry\u street\u address），则查询会将街道地址带给我，但我还需要地址中的状态。Thanx prevenly

您的CASE语句构造错误。像这样使用它：

SELECT o.rfq_id, s.name, m.manufacturers_name, o.ship_address, o.serial, o.model, d.part_type,        d.description, d.part_number, d.subs, d.qty, o.notes, d.action, d.vendor, d.pt, d.price2, d.buy, d.notes1, o.tracking_number, o.date_shipped, o.expected_date, o.po_no, o.issue_no, o.date_added, 
       CONCAT_WS(' ', c.customers_lastname, c.customers_firstname) AS customer_name,
       c.customers_email_address,
       CASE
           WHEN o.ship_address = 0 THEN (a.entry_street_address,
                                         a.entry_state)
           WHEN o.ship_address = 1 THEN (p.street_address,
                                         p.state)
       END AS Address
FROM rfq_order o
JOIN rfq_order_detail d ON o.rfq_id = d.rfq_id
JOIN customers c ON o.customer_id = c.customers_id
JOIN address_book a ON c.customers_id = a.customers_id
JOIN manufacturers e ON o.manufacturer = e.manufacturers_id
JOIN manufacturers m ON o.manufacturer = m.manufacturers_id
JOIN rfq_order_status s ON o.status = s.id
LEFT JOIN shipping_address p ON o.rfq_id = p.rfq_id

或：

---

您也不能将多个列放在那里，它是一列。如果确实需要更多的列，则必须将它们串联起来，或者复制case语句。

或者使用两个

concat

列，或者使用两个

case

语句

 CASE WHEN cond THEN exp1
     WHEN cond2 THEN exp2
     ELSE exp3 END

或

---

当o.ship\u address=0时，那么a.entry\u street\u address ELSE p.street\u address当o.ship\u address=0时，那么a.entry\u state ELSE p.state END AS address我应该这样做吗？Thanx很多。我使用两个案例时是错的。现在可以工作了。如果我使用你的或部分bcoj，我希望街道与州分开，这会给我错误。第一个是工作第二种方法有两种情况，当您为每个操作数输入（a.entry\u street\u address）时有效，否则将导致SQL错误

 CASE WHEN cond THEN exp1
     WHEN cond2 THEN exp2
     ELSE exp3 END

SELECT  ...
       CASE
           WHEN o.ship_address = 0 THEN concat(a.entry_street_address,
                                         a.entry_state)
           WHEN o.ship_address = 1 THEN concat(p.street_address,
                                         p.state)
       END AS Address

SELECT  ...
       CASE
           WHEN o.ship_address = 0 THEN a.entry_street_address
           WHEN o.ship_address = 1 THEN p.street_address
       END AS StreetAddress,
       CASE
           WHEN o.ship_address = 0 THEN a.entry_state
           WHEN o.ship_address = 1 THEN p.state
       END AS State,