如何将以下 3 个表 SQL 查询转换为 Grails?
SELECT t.name, count(*) as c
FROM topic t
LEFT OUTER JOIN article_topics at
ON t.id = at.topic_id
LEFT OUTER JOIN article a
ON at.article_id = a.id
GROUP BY t.name
我一直在尝试类似于但不确定如何进行连接的方法
def criteria = Topic.createCriteria()
criteria.list {
groupProperty("name")
projections {
count('*')
}
}
或者如果我尝试使用它可能会更好/更容易
Topic.executeQuery(..insert sql..)
如果有帮助,我有文章和主题 GORM 对象和文章
static mapping = {
topics lazy: false, joinTable: [name: 'article_topics', column: 'topic_id', key: 'article_id']
}
最佳答案
托德。在 grails 中,您可以使用本文 post 中所述的休眠原生 sql 查询。哈基先生。
我分享了一个取自生产代码的示例,该示例使用出版物中描述的技术并使用左连接。
List<Map<String, Object>> resumeInMonth(final String monthName) {
final session = sessionFactory.currentSession
final String query = """
SELECT
t.id AS id,
e.full_name AS fullName,
t.subject AS issue,
CASE t.status
WHEN 'open' THEN 'open'
WHEN 'pending' THEN 'In progress'
WHEN 'closed' THEN 'closed'
END AS status,
CASE t.scheduled
WHEN TRUE THEN 'scheduled'
WHEN FALSE THEN 'non-scheduled'
END AS scheduled,
ifnull(d.name, '') AS device,
DATE(t.date_created) AS dateCreated,
DATE(t.last_updated) AS lastUpdated,
IFNULL(total_tasks, 0) AS tasks
FROM
tickets t
INNER JOIN
employees e ON t.employee_id = e.id
LEFT JOIN
devices d ON d.id = t.device_id
LEFT JOIN
(SELECT
ticket_id, COUNT(1) AS total_tasks
FROM
tasks
GROUP BY ticket_id) ta ON t.id = ta.ticket_id
WHERE
MONTHNAME(t.date_created) = :monthName
ORDER BY dateCreated DESC
"""
final sqlQuery = session.createSQLQuery(query)
final results = sqlQuery.with {
resultTransformer = AliasToEntityMapResultTransformer.INSTANCE
setString('monthName', monthName)
list()
}
results
}
我希望它对你有用
关于grails - 将 SQL 查询转换为 Grails,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/46494079/