codeigniter - 代码点火器总是逃避我的 SELECT ... CASE 查询

Question

我正在使用 Codeigniter 对我的数据库进行查询。代码如下:

$this->db->select("category.Name,
booking.Comment,
CASE WHEN amount > 0 THEN amount END AS PosAmount,
CASE WHEN amount < 0 THEN amount END AS NegAmount");

但我总是得到一个

You have an error in your SQL syntax ... right syntax to use near
'WHEN amount > 0 THEN amount END AS PosAmount, `CASE` WHEN amount < 0 
THEN amount' at line 1

Codeigniter 正在逃避 CASE，但我不知道如何防止这种情况发生。

有任何想法吗？

Answer 1

来自 documentation :

$this->db->select() accepts an optional second parameter. If you set it to FALSE, CodeIgniter will not try to protect your field or table names. This is useful if you need a compound select statement where automatic escaping of fields may break them.

在你的情况下:

$this->db->select("category.Name,
booking.Comment,
CASE WHEN amount > 0 THEN amount END AS PosAmount,
CASE WHEN amount < 0 THEN amount END AS NegAmount", FALSE);

第二个参数也可用于 where 和 join 子句。