我正在尝试将这个问题中的查询转换为 mySql，因为我们将数据从访问数据库移动到新结构。
我想出了以下内容，因为有多个条件（“值”或“未竞争”），并且我收到以下错误（已解决，请参阅下面的编辑 2）。
1064 - 您的 SQL 语法有错误；检查与您的 MariaDB 服务器版本相对应的手册，以获取正确的语法，以便在 'then 0 else 1 end) AS 'Total Weapons', SUM( case when ( tourney_info.c_we' at line 7) 附近使用
查询如下：
SELECT school_num, 'Total Form and Sparring', 'Total Weapons', 'Total Combat', 'Total Form and Sparring' + 'Total Weapons' + 'Total Combat' AS 'Total Entries'
FROM
(
SELECT
tourney_info.school_num,
SUM( case when tourney_info.t_forms IN ('', 'Did Not Compete') AND tourney_info.spar IN ('','Did Not Compete')
then 0
else 1
end) AS 'Total Form and Sparring',
SUM( case when tourney_info.t_weps IN ('','Did Not Compete') then 0 else 1 end) AS 'Total Weapons',
SUM( case when tourney_info.c_weps IN ('', 'Did Not Compete') then 0 else 1 end) AS 'Total Combat'
FROM
tourney_info
WHERE school_num = '546' AND tourn_date > '2018-04-20' AND tourn_date < '2018-04-22'
) AS derived
根据评论解决错误后，查询将提供以下结果：
school_num Total Form and Sparring Total Weapons Total Combat Total Entries
546 Total Form and Sparring Total Weapons Total Combat 0
编辑 #2，在查看字段规范后，作为测试查询显示有人将字段设置为 10 个字符，并且我的“不竞争”在导入时被截断：
如果我按如下方式取出内部查询，我会得到个人总数，但是我没有得到累计总数：
SELECT
tourney_info.school_num, 'Total Form and Sparring' + 'Total Weapons' + 'Total Combat' AS 'Total Entries',
SUM( case when tourney_info.t_forms IN ('', 'Did Not Co') AND tourney_info.spar IN ('','Did Not Co')
then 0
else 1
end) AS 'Total Form and Sparring',
SUM( case when tourney_info.t_weps IN ('','Did Not Co') then 0 else 1 end) AS 'Total Weapons',
SUM( case when tourney_info.c_weps IN ('','Did Not Co') then 0 else 1 end) AS 'Total Combat'
FROM
tourney_info
WHERE tourney_info.school_num = '546' AND tourney_info.tourn_date > '2018-04-20' AND tourney_info.tourn_date < '2018-04-22'
结果集：
school_num Total Entries Total Form and Sparring Total Weapons Total Combat
546 0 36 17 25
在最新的迭代（编辑#5）中，问题是您不能在声明它们的查询中使用列别名。您可以返回原始查询（获取子查询中每个类别的总数，并使用主查询中的别名将它们加在一起），或者执行以下操作：
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这是因为“布尔”表达式的计算结果为 1（真）或 0（假）。