我有以下表格：
Amortization Table
+----------------+--------------+--------------+--------------+
|amortization_id | contract_id | due_date | amount |
+----------------+--------------+--------------+--------------+
| 1 | 2 | 2017-03-15 | 1000.00 |
| | | | |
| 2 | 2 | 2017-04-15 | 1500.00 |
| | | | |
| 3 | 3 | 2017-08-03 | 5000.00 |
| | | | |
| 4 | 3 | 2017-09-03 | 5000.00 |
| | | | |
| 5 | 3 | 2017-10-03 | 5000.00 |
+----------------+--------------+--------------+--------------+
Contract Table
+----------------+--------------+--------------+--------------+
| contract_id | project_id |contract_name | person_id |
+----------------+--------------+--------------+--------------+
| 1 | 1 | Xavier Ville | 33 |
| | | | |
| 2 | 1 | Camella Homes| 45 |
| | | | |
| 3 | 2 | Burmingham | 61 |
+----------------+--------------+--------------+--------------+
Project Table
+----------------+-------------------+
| project _id | project_name |
+----------------+-------------------+
| 1 | Samporna Project |
| | |
| 2 | Velasco Project |
+----------------+-------------------+
Person Table
+-------------+-------------------+
| person_id | person_name |
+-------------+-------------------+
| 33 | Glenn Henley |
| | |
| 45 | Alexa Gahisan |
| | |
| 61 | Glynis Walters |
+-------------+-------------------+
如何查询Codeigniter Active Record以获得以下结果：
+-----------+-------------------+-----------------+-------------+-------+
|contract_id| contract_name | project_name | person_name |january|
+-----------+-------------------+-----------------+-------------+-------+
| 2 | Camella Homes | Samporna Project|Alexa Gahisan|0 |
| | | | | |
| 3 | Burmingham | Velasco Project |Glynis Walter|0 |
+-------------+-----------------+-----------------+-------------+-------+
Continuation of table above in horizontal
+--------+-------+-------+---+----+----+--------+---------+---------+
|february| march | april |may|june|july| august |september| october |
+--------+-------+-------+---+----+----+--------+---------+---------+
| 0 | 1000 | 1500 | 0 | 0 |0 |0 |0 |0 |
| | | | | | | | | |
| 0 | 0 | 0 | 0 | 0 |0 |5000 |5000 |5000 |
+--------+-------+-------+---+----+----+--------+---------+---------+
使查询显示基于分配月份的摊销金额。在过去的几天里，这对我来说非常具有挑战性。到目前为止，我在我的模型中使用了这个代码，它返回一个错误，说子查询返回多个。
$year=date("Y");
$this->db->select('a.*');
$this->db->select('(select c.amortization_amount from amortization c where YEAR(c.due_date) ='.$year.' and MONTH(c.due_date) = 01 and c.contract_id=a.contract_id and c.paid_up=0 and c.line_type=4) as january',FALSE);
$this->db->select('(select d.amortization_amount from amortization d where YEAR(d.due_date) ='.$year.' and MONTH(d .due_date) = 02 and d.contract_id=a.contract_id and d.paid_up=0 and d.line_type=4) as february',FALSE);
$this->db->select('(select e.amortization_amount from amortization e where YEAR(e.due_date) ='.$year.' and MONTH(e.due_date) = 03 and e.contract_id=a.contract_id and e.paid_up=0 and e.line_type=4) as march',FALSE);
$this->db->select('(select f.amortization_amount from amortization f where YEAR(f.due_date) ='.$year.' and MONTH(f.due_date) = 04 and f.contract_id=a.contract_id and f.paid_up=0 and f.line_type=4) as april',FALSE);
$this->db->select('(select g.amortization_amount from amortization g where YEAR(g.due_date) ='.$year.' and MONTH(g.due_date) = 05 and g.contract_id=a.contract_id and g.paid_up=0 and g.line_type=4) as may',FALSE);
$this->db->select('(select h.amortization_amount from amortization h where YEAR(h.due_date) ='.$year.' and MONTH(h.due_date) = 06 and h.contract_id=a.contract_id and h.paid_up=0 and h.line_type=4) as june',FALSE);
$this->db->select('(select i.amortization_amount from amortization i where YEAR(i.due_date) ='.$year.' and MONTH(i.due_date) = 07 and i.contract_id=a.contract_id and i.paid_up=0 and i.line_type=4) as july',FALSE);
$this->db->select('(select j.amortization_amount from amortization j where YEAR(j.due_date) ='.$year.' and MONTH(j.due_date) = 08 and j.contract_id=a.contract_id and j.paid_up=0 and j.line_type=4) as august',FALSE);
$this->db->select('(select k.amortization_amount from amortization k where YEAR(k.due_date) ='.$year.' and MONTH(k.due_date) = 09 and k.contract_id=a.contract_id and k.paid_up=0 and k.line_type=4) as september',FALSE);
$this->db->select('(select l.amortization_amount from amortization l where YEAR(l.due_date) ='.$year.' and MONTH(l.due_date) = 10 and l.contract_id=a.contract_id and l.paid_up=0 and l.line_type=4) as october',FALSE);
$this->db->select('(select m.amortization_amount from amortization m where YEAR(m.due_date) ='.$year.' and MONTH(m.due_date) = 11 and m.contract_id=a.contract_id and m.paid_up=0 and m.line_type=4) as november',FALSE);
$this->db->select('(select n.amortization_amount from amortization n where YEAR(n.due_date) ='.$year.' and MONTH(n.due_date) = 12 and n.contract_id=a.contract_id and n.paid_up=0 and n.line_type=4) as december',FALSE);
$this->db->from('contract a');
$this->db->group_by('a.contract_id');
$query = $this->db->get();
return $query->result_array();
因为我不想在我的javascript中做很多工作。我想知道是否有任何方法可以使用Codeigniter的Active Record在sql查询中执行此操作。
答案 0 :(得分：0)
要快速修复当前代码，您可以为每个子查询添加List<Integer> one = new ArrayList<>();
List<Double> two = new ArrayList<>();
List<Number> aSuper = getSuper(one, two);
，例如...... limit 1 ...
您也可以使用连接重写此方法，因为您可以在同一个表上反复and l.line_type=4 limit 1) as october。如果每个子查询中确实有多行，则可能必须使用left join或类似的行。