sql - 语法错误:使用计数和内部联接进行SQL更新

Question

我有两个表：

CREATE TABLE user (
ticketId integer not null,
eventId integer not null,
ticketUsed integer, 
userName text not null,
FOREIGN KEY (ticketId) REFERENCES ticketType (ticketId)
);

和

CREATE TABLE ticketType ( 
eventId integer not null, 
ticketId integer unique not null,
ticketsUsed integer,
FOREIGN KEY (eventId) REFERENCES event (eventId)
);

我正在尝试根据使用的票证更新 ticketType.ticketsUsed

UPDATE ticketType 
SET ticketsUsed = (SELECT COUNT(*) FROM user as u WHERE ticketUsed=1)
WHERE ticketId = u.ticketId;

但是我得到一个错误：


错误：无此列：u.ticketId

UPDATE ticketType
SET ticketsUsed = us.count
FROM ticketType
INNER JOIN (SELECT ticketId, COUNT(*) as count FROM user  WHERE ticketUsed=1 group by ticketId) us 
ON us.ticketId=ticketType.ticketId
WHERE eventId = 23779;

错误：“ FROM”附近：语法错误

Answer 1

您必须将ticketId过滤器放入子查询中：

UPDATE ticketType
SET ticketsUsed = (SELECT COUNT(*)
                   FROM user AS u
                   WHERE ticketUsed = 1
                     AND u.ticketId = ticketType.ticketId)