mongodb - 使用迭代动态构建条件 block

Question

我想基于几个过滤器查询属性并动态建立条件

Domain Class
PatientAttr {
   def name
   def value
}

标准构建代码

    if(filters.size() != 0 ){
        def criteria =  PatientAttr.createCriteria()
        def results = criteria.list{
            for (item in filters){
                def name = item.name
                def filter = item.filter
                and{
                    eq 'name', name
                    if(filter[0] == "lt")
                        lt ('value', filter[1] as Double)
                    else if(filter[0] == "gt")
                        gt ('value', filter[1] as Double)
                    else 
                        between ('value', filter[0] as Double, filter[1] as Double)
                }
            }
        } 

我发现，仅对列表的最后一个“和”语句进行评估。条件构建器是否允许您动态构建条件？

上面的代码应与此等效

        def results = criteria.list{
            and{
                eq 'name', "Serum albumin (g/dL)"
                gt 'value', 3.5 as Float
            }
            and{    
                eq 'name', "M-spike (g/dL)"
                gt 'value', 2.3 as Float
            }
        }

Answer 1

我不知道您为什么会遇到麻烦，但是由于查询的默认联合词是and，因此根本没有理由在示例中使用and{}闭包。您上面的查询与以下内容相同:

    def results = criteria.list{
        eq 'name', "Serum albumin (g/dL)"
        gt 'value', 3.5 as Float
        eq 'name', "M-spike (g/dL)"
        gt 'value', 2.3 as Float
    }

如果要将最上面的项目 or放在一起，则需要将外部块包装在 or{}闭包中:

if(filters.size() != 0 ){
    def criteria =  PatientAttr.createCriteria()
    def results = criteria.list{
        or{
            for (item in filters){
                def name = item.name
                def filter = item.filter
                and{
                    eq 'name', name
                    if(filter[0] == "lt")
                        lt ('value', filter[1] as Double)
                    else if(filter[0] == "gt")
                        gt ('value', filter[1] as Double)
                    else 
                        between ('value', filter[0] as Double, filter[1] as Double)
                }
            }
        }
    } 

这将返回一个查询，其结果如下:

name is 'Serum albumin...' and value is greater than '3.5'
OR
name is 'M-spike...' and value is greater than 2.3
OR etc

希望有帮助。