Question

| Grails版本：3.0.9 | Groovy版本：2.4.5 | JVM版本：1.8.0_60

您好，

我有以下GORM查询，涉及＆＃39;事件＆＃39;之间的联接。和＆＃39; EventCategory＆＃39;带有页面结果的域对象。

def advancedSearchWithPagedResults(int max, int offset, String search, Date startDate, Date endDate, List myEventCategories) {

    // need to convert our list of ints to longs as the field they'll be compared to is a long
    def listOfLongs = myEventCategories.collect {
        it.toLong()
    }

    def wildcardSearch = search ? '%' + search + '%' : '%'

    def ids = Event.createCriteria().list {

        projections {
            distinct 'id'
        }

        maxResults max
        firstResult offset

        or {
            like("eventName", wildcardSearch)
            like("address.town", wildcardSearch)
            like("address.county", wildcardSearch)
        }
        and {
            if (listOfLongs) {
                eventCategories {
                    'in'("id", listOfLongs)
                }
            }
            between("startDateTime", startDate, endDate)
            eq("enabled", true)
        }
        order("startDateTime", "asc")
    }

    /* Get the acual events using the list of id's just obtained */
    def results = Event.getAll(ids)

    return results
}

但是，我需要添加/合并以下MySQL查询，该查询计算每个事件（以英里为单位）与提供的入口和经度（51.519159，-0.133190）之间的距离，然后过滤掉任何超出的事件25英里（在这个例子中）。事件也按照提供的纬度/经度的距离排序。

SELECT 
  `event`.*, 
   ( 3959 * acos( cos( radians(51.519159) ) * cos( radians( `event`.address_latitude ) ) 
   * cos( radians(`event`.address_longitude) - radians(-0.133190)) + sin(radians(51.519159)) 
   * sin( radians(`event`.address_latitude)))) AS distance 
FROM `event` 
WHERE `event`.enabled = 1 
HAVING distance < 25 
ORDER BY distance;

我的问题是如何最好地改变GORM查询以纳入距离计算？

我是否需要抛弃GORM查询并使用本机HQL查询？我不希望。

任何想法都会非常感激。

为了完整起见，我将包含两个域对象的相关部分。

class Event implements Taggable {

    static hasMany = [courses:          Course,
                      eventCategories:  EventCategory,
                      faqs:             FAQ]

    static belongsTo = [eventOrganiser:     EventOrganiser]

    java.util.Date dateCreated
    java.util.Date lastUpdated
    boolean enabled = true
    String eventName
    String organisersDescription
    @BindingFormat('dd/MM/yyyy HH:mm')
    java.util.Date startDateTime
    @BindingFormat('dd/MM/yyyy HH:mm')
    java.util.Date endDateTime
    @BindingFormat('dd/MM/yyyy HH:mm')
    java.util.Date entriesOpenDateTime
    @BindingFormat('dd/MM/yyyy HH:mm')
    java.util.Date entriesCloseDateTime
    BigDecimal fromPrice
    Address address
    Contact primaryContact

    static embedded = ['address','primaryContact']

    // transient fields
    double distanceFromUsersPostcode
    ....
}

class EventCategory {

    static hasMany = [events:Event]
    static belongsTo = [Event]

    String parentCategoryName
    String parentSubCategoryName
    String categoryName
    String description

    int order
}

Answer 1

您可以在域类内部将距离查询存储为formula，然后将其作为该类的属性进行调用。

活动类：

static mapping = {
    distance formula: """
        (3959 * acos(cos(radians(51.519159)) * 
        cos(radians(ADDRESS_LATITUDE)) * cos( radians(ADDRESS_LONGITUDE) - 
        radians(-0.133190)) + sin(radians(51.519159)) * sin( radians(ADDRESS_LATITUDE))))
    """
}

您可能需要尝试使用公式字符串（新行字符是否会导致问题）。似乎查询的几个部分都是常量，可以将其排除在外：acos(cos(radians(51.519159))，radians(-0.133190)，sin(radians(51.519159))

Criteria Builder

您现在可以像使用其他任何属性一样使用distance属性：

lt('distance', 25)

GORM中的复杂查询涉及MySQL函数cos，弧度

1 个答案: