我正试图允许一个特定的 SELECT 基于发送到 IF 条件。例如，如果用户从下拉列表中选择了support，则会向sql语句发送一个变量键，并使用适当的 SELECT 语句被执行。
DECLARE @ strg
SET @strg = 'input string'
IF(SELECT * FROM tickets WHERE ticket_section = @strg)
BEGIN
SELECT
usr_users.uname AS `user`,
support_chat_user.message AS user_message,
support_chat_user.created AS user_chat_date,
support_ticket.`subject` AS ticket_subject,
support_ticket.`status` AS ticket_state,
support_ticket.created AS ticket_date,
support_ticket.modified AS updated_date,
tickets.state
FROM
tickets
INNER JOIN support_chat_user ON support_chat_user.tickets_id = tickets.tick_id
INNER JOIN support_ticket ON support_ticket.tickets_id = tickets.tick_id
INNER JOIN usr_users ON support_chat_user.reporter_id = usr_users.uid
WHERE
tickets.tick_id = '9' AND
usr_users.uid = '1'
END
IF EXISTS(SELECT * FROM tickets WHERE ticket_section = @strg)
BEGIN
SELECT
usr_users.uname AS `user`,
support_chat_user.message AS user_message,
support_chat_user.created AS user_chat_date,
support_ticket.`subject` AS ticket_subject,
tickets.state
FROM
tickets
INNER JOIN support_chat_user ON support_chat_user.tickets_id = tickets.tick_id
INNER JOIN support_ticket ON support_ticket.tickets_id = tickets.tick_id
INNER JOIN usr_users ON support_chat_user.reporter_id = usr_users.uid
WHERE
tickets.tick_id = '9' AND
usr_users.uid = '1'
END
1条答案
按热度按时间s3fp2yjn1#
mysql不支持
IF，除非将代码放入编程块中。你的问题有点难理解，因为文本中提到了一个查询，但代码是两个似乎相同的查询。您可以将条件逻辑移到最外层
WHERE查询中的子句：我不确定这是你真正想要的。我怀疑你想要：
然而，这仅仅是关于在你描述的情况下什么是有用的知情推测。
笔记：
表别名使查询更易于编写和读取（正确的缩进也是如此）。
数字常量不应该用单引号引起来。我猜身份证真的是数字。如果它们是字符串，那么单引号是合适的。