Moodle SQL 语句显示已发送给具有特殊 ID 的用户的所有消息

Question

如何使用SQL查询哪些消息发送给了ID为100的用户？

Answer 1

Moodle 中有 2 个消息表，分别是消息被读取之前和之后

||

是Postgresql中的连接运算符

SELECT 'message' || id AS uniqueid,
    useridfrom,
    useridto,
    subject,
    fullmessage,
    contexturl,
    contexturlname,
    timecreated,
    0 AS timeread,
    timeuserfromdeleted,
    timeusertodeleted
FROM mdl_message
WHERE useridfrom = xx
UNION
SELECT 'messageread' || id AS uniqueid,
    useridfrom,
    useridto,
    subject,
    fullmessage,
    contexturl,
    contexturlname,
    timecreated,
    timeread,
    timeuserfromdeleted,
    timeusertodeleted
FROM mdl_message_read
WHERE useridfrom = xx