Question

我有一个哈希数组。

SELECT persons.* FROM persons WHERE persons.id = 20 AND persons.name = 'John' OR persons.id = 30 AND persons.name = 'Doe'

我想获得符合特定哈希中所有条件的记录。所以我想要执行的查询是

static double incrTrueBinaryErr = 62.5;
static double incrTrueBinaryMov = 31.25;
static double incr01001 = 360000;
static double incr_1101 = 125;
static double incr05008 = 3600000;
static double incr10004 = 1024000;
static double incr22000 = 1000;
static double incr22001 = 1000;

Date currDate;

    while (true)
    {
    currDate = new Date();

    if (currDate.getTime() == currDate.getTime() + incrTrueBinaryErr)
        //do stuff

    if (currDate.getTime() == currDate.getTime() + incrTrueBinaryMov)
        //do stuff

    if (currDate.getTime() == currDate.getTime() + incr01001)
        //do stuff

    if (currDate.getTime() == currDate.getTime() + incr_1101)
        //do stuff

    if (currDate.getTime() == currDate.getTime() + incr05008)
        //do stuff

    if (currDate.getTime() == currDate.getTime() + incr10004)
        //do stuff

    if (currDate.getTime() == currDate.getTime() + incr22000)
        //do stuff

    if (currDate.getTime() == currDate.getTime() + incr22001)
        //do stuff

    }

从哈希数组构造此查询的最佳方法是什么？

Answer 1

尝试将所有条件独立映射到ActiveRecord模型，然后展平结果数组：

array_of_hash.map{ |where_clause| Person.where(where_clause) }.flatten

Answer 2

我认为这没关系：

ids = array_of_hash.map { |h| h[:id] }
names = array_of_hash.map { |h| h[:name] }

Person.where(id: ids, name: names)

（虽然它不是超级通用的）其他尝试：

people = Person.all
array_of_hash.each do |h|
  people = people.where(h)
end
people # => will generate a long long query.

ActiveRecord从哈希数组中查询

2 个答案: