在 codeigniter 查询生成器中使用联合，并在虚拟 mysql 列中过滤

Question

在我的项目中，我使用带有服务器端处理的数据表插件。在我进行搜索或排序（排序）操作之前，它工作正常，因为它需要活动记录才能做到这一点。

我的场景是，我有一个帐户表、收入表和付款表，我想查看收入和付款表的所有数据，这就是我需要工会的原因。我的查询如下---

SELECT 'Income' as source, fld_type, fld_amount, ta.fld_account as account,  fld_date, tbl_revenue.fld_description as fld_traninfo, tbl_revenue.fld_created as created
        FROM tbl_revenue JOIN tbl_accounts as ta on tbl_revenue.fld_account_id = ta.fld_id
UNION
SELECT 'Expense' as source, fld_type, fld_amount, tae.fld_account, fld_date, tbl_payment.fld_description as fld_traninfo, tbl_payment.fld_created as created
        FROM tbl_payment JOIN tbl_accounts as tae on tbl_payment.fld_account_id = tae.fld_id

有没有办法在这个查询中使用查询生成器？

第二个问题，您可以看到我创建了一个名为“source”的虚拟列，我想使用 where 子句过滤此列并附加此查询，如下所示

WHERE source like "%a%" limit(10,0)

但是这返回我没有任何列名'source'，我该如何过滤这个列？

感谢任何帮助。

Answer 1

有一种方法可以做到这一点，但它有点hacky，因为如果你没有自己指定，codeigniter 的 querybuilder 会在查询中添加一个自动 SELECT 语句

为了得到你想要的，你必须将你的选择语句分成 2 个查询，并将 where 子句添加到这个查询中

类似的东西应该可以工作：

$strQuery1 = $this->db
    ->select('income as source, fld_type, fld_amount, ta.fld_account as account,  fld_date, tbl_revenue.fld_description as fld_traninfo, tbl_revenue.fld_created as created')
    ->from('tbl_revenue')
    ->join('tbl_accounts as ta', 'tbl_revenue.fld_account_id = ta.fld_id')
    ->get_compiled_select();

$strQuery2 = $this->db
    ->select('Expense as source, fld_type, fld_amount, ta.fld_account as account,  fld_date, tbl_revenue.fld_description as fld_traninfo, tbl_revenue.fld_created as created')
    ->from('tbl_payment')
    ->join('tbl_accounts as ta', 'tbl_revenue.fld_account_id = ta.fld_id')
    ->get_compiled_select();

$strWhere = substr($this->db->like('source', 'a', 'both')->get_compiled_select(), 8);

$query = $this->db->query($strQuery1.' UNION '.$strQuery2.$strWhere);