从另一个 table SQL 的值更新列值

Question

我有一个 table chatmessages，其中包含 chatId、incomingId、outgoingId 列，我还有另一个 table chatmembers，其中包含 chatId、usersId 列。还有另一个 table chat，它只包含 chatId，以及聊天的 usersId 初始值设定项，即 user1

现在，我想将 chatId 从 chatmembers 复制到 chatmessages 其中有相同的用户，例如， incomingId 83 和 outgoingId 81 在 [=14 中具有相同的 chatId =]

我有这个查询，但它不起作用

UPDATE chatmessages SET chatId = 
(SELECT c.chatId FROM chat AS c INNER JOIN (SELECT chatId FROM chatmembers WHERE usersId = incomingId) AS uc ON c.chatId = uc.chatId 
INNER JOIN (SELECT chatId FROM chatmembers WHERE companyId = outgoingId) AS cc ON uc.chatId = cc.chatId)

Answer 1

如果我没理解错的话，你可以使用joins。以下使用 MySQL 语法：

update chatmessages cm join
       chatusers cuo
       on cuo.userid = cm.outgoingid join
       chatusers cui
       on cui.userid = cm.incomingid and
          cui.chatid = cuo.chatid
   set cm.chatid = cuo.chatid;

Answer 2

您必须将此查询写入数组，然后执行，在

中也使用双引号

(SELECT c.chatId FROM chat AS c 
INNER JOIN (SELECT chatId FROM chatmembers WHERE usersId = incomingId) AS uc ON c.chatId = uc.chatId 
INNER JOIN (SELECT chatId FROM chatmembers WHERE companyId = outgoingId)

像这样

("SELECT c.chatId FROM chat AS c 
INNER JOIN (SELECT chatId FROM chatmembers WHERE usersId = incomingId) AS uc ON c.chatId = uc.chatId 
INNER JOIN (SELECT chatId FROM chatmembers WHERE companyId = outgoingId")

从另一个 table SQL 的值更新列值

Updating a column value from the value of the other table SQL

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