mysql - 如何在 Grails 2.4.0 中编写原生 SQL 查询？

Question

我正在开发 Grails 2.4.0。我想在 Groovy Controller 中执行 native 查询。查询如下:

SELECT AVG(REPLACE(n.ep_text, 'PPM', '')), MONTH(n.date_creat) 
from notification n
where n.type = 42
GROUP BY MONTH(n.date_creat)

首先，我执行上面的查询，但它没有找到REPLACE函数，例如:

String query1 = "SELECT n.id, avg(REPLACE(n.epText, 'PPM', '')) FROM Notification as n";
def result  = Notification.executeQuery(query1.toString())

我怎样才能执行其中的REPLACE函数？

其次，我对此进行了一些研发，但执行 native 查询需要 sessionFactory。无法理解如何在 Grails 2.4.0 中获取 Hibernate 的当前 session 来执行 native 查询？

如有任何帮助，我们将不胜感激。

Answer 1

为了使用 native 查询，我们可以使用 SessionFactory，它是一个 bean，我们可以简单地向 Grails Controller 或服务声明它，依赖注入(inject)将处理它。以下是使用此 bean 执行 native 查询的示例代码。

class PublicService {
    def sessionFactory
    def getMatchedValue(){
        def currentSession = sessionFactory.currentSession
        def q = "select bank.id as id, bank.credit_amount as creditAmount, bank.debit_amount as debitAmount, bank.transaction_date as transactionDate, bank.transaction_name as transactionName, receipt.cr_date as crDate, receipt.picture_reference as pictureReference, receipt.receipt_date as receiptDate, receipt.reimbursment as reimbursment, receipt.total_amount as totalAmount, receipt.vendor as vendor " +
                "from bank inner join receipt on bank.debit_amount=receipt.total_amount where ((bank.transaction_date >= receipt.receipt_date) and (bank.transaction_date <= DATE_ADD(receipt.receipt_date, INTERVAL 5 DAY) ))"//sample native query
        def data = currentSession.createSQLQuery(q)
        data.setResultTransformer(Criteria.ALIAS_TO_ENTITY_MAP);//if you are using alias for query e.g bank.credit_amount as creditAmount
        final result = data.list()
        return result
    }
}