带有左连接和日期函数的 MySQL 查询的 Grails 标准或 HQL答案

【问题标题】：Grails criteria or HQL for MySQL query with left join and date functions带有左连接和日期函数的 MySQL 查询的 Grails 标准或 HQL
【发布时间】：2012-11-02 00:10:29
【问题描述】：

我有一个 MySQL 数据库，其中存储了某些商品的销售额。我想比较过去两天的销售额，例如过去 10 天和过去 9 天。为此，我制定了 MySQL 查询：

select s1.sales - s2.sales from ProductSales as s1
left join ProductSales as s2 on s2.date >= DATE(DATE_ADD(Now(), INTERVAL '-10' DAY)) and s2.date <= DATE(DATE_ADD(Now(), INTERVAL '-9' DAY)) and s2.product_id = s1.product_id
where s1.date >= DATE(DATE_ADD(Now(), INTERVAL '-9' DAY));

我想在 Grails 应用程序中以编程方式执行此操作，我需要将此查询转换为条件或 HQL 查询。我该怎么做？

更新：我试过这样：

def date1 = new Date() - 2
def date2 = new Date() - 1
def sales = ProductSales.executeQuery( """
    select s1.sales - s2.sales from ProductSales s1
    left join ProductSales s2
    where s1.date >= :date2
    and s2.date >= :date1 and s2.date < :date2 and s2.product_id = s1.product_id""",
[ date1: date1, date2: date2 ] )

不幸的是，这给了我：

ERROR hql.ast.ErrorCounter -  Path expected for join!
ERROR hql.ast.ErrorCounter -  Invalid path: 's2.sales'
ERROR hql.ast.ErrorCounter -  right-hand operand of a binary operator was null
ERROR hql.ast.ErrorCounter -  Invalid path: 's2.date'
ERROR hql.ast.ErrorCounter - <AST>:0:0: unexpected end of subtree
ERROR hql.ast.ErrorCounter -  left-hand operand of a binary operator was null
ERROR hql.ast.ErrorCounter -  Invalid path: 's2.date'
ERROR hql.ast.ErrorCounter - <AST>:0:0: unexpected end of subtree
ERROR hql.ast.ErrorCounter -  left-hand operand of a binary operator was null
ERROR hql.ast.ErrorCounter -  Invalid path: 's2.product_id'
ERROR hql.ast.ErrorCounter - <AST>:0:0: unexpected end of subtree
ERROR hql.ast.ErrorCounter -  left-hand operand of a binary operator was null
ERROR logging.impl.SLF4JLog - QuerySyntaxException occurred when processing request: [GET] /app/dashboard
Path expected for join!

更新 2：由于我无法回答我自己的问题，我在此处添加我的回复：

显然这是应该的：

def now = new Date()
def date1 = now - 2
def date2 = now - 1
def sales = ProductSales.executeQuery( """
    select s1.owner, s1.sales - s2.sales from ProductSales s1, ProductSales s2
    where s1.date >= :date2 and s1.date < :now 
    and s2.date >= :date1 and s2.date < :date2 and s2.product = s1.product""",
    [ date1: date1, date2: date2, now: now ]
    )

不过，我不完全确定 left join 和 select from T1, T2 之间有什么区别。除此之外，我为最近的条目添加了一个上限 (now)，并将 product_id 更改为 product。

【问题讨论】：

标签： mysql grails hql

【解决方案1】：

显然这是应该的：

def now = new Date()
def date1 = now - 2
def date2 = now - 1
def sales = ProductSales.executeQuery( """
    select s1.owner, s1.sales - s2.sales from ProductSales s1, ProductSales s2
    where s1.date >= :date2 and s1.date < :now 
    and s2.date >= :date1 and s2.date < :date2 and s2.product = s1.product""",
    [ date1: date1, date2: date2, now: now ]
    )

不过，我不完全确定 left join 和 select from T1, T2 之间有什么区别。除此之外，我为最近的条目添加了一个上限 (now)，并将 product_id 更改为 product。

【讨论】：