Mysql 在 codeigniter 中查询求和查询

Question

以上link是我的问题之一。我得到了上述问题的答案。但是现在我有一个 sql 查询如下，

SELECT SUM(IF(pay_type = 1, `pay_amount`, `0))` mess_pay, SUM(IF(pay_type=2, `pay_amount`, `0))` est_pay FROM (`mess_stock`);

我想在 codeigniter 中使用上面的代码。

我试过下面的方法

$this->db->select('SUM(IF(pay_type = 1, pay_amount, 0)) mess_pay, SUM(IF(pay_type=2, pay_amount, 0)) est_pay');
$this->db->from('mess_stock');

但它抛出以下输出

A Database Error Occurred
Error Number: 1064
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'mess_pay, SUM(IF(pay_type=2, `pay_amount`, `0))` est_pay FROM (`mess_stock`)' at line 1


SELECT SUM(IF(pay_type = 1, `pay_amount`, `0))` mess_pay, SUM(IF(pay_type=2, `pay_amount`, `0))` est_pay FROM (`mess_stock`)


Filename: /var/www/college/modules/mess_fees/models/mess_fees_model.php
Line Number: 25

如何执行上述查询？

Answer 1

将 select() 的最后一个参数设置为 false :

$this->db->select('SUM(IF(pay_type = 1, pay_amount, 0)) mess_pay, SUM(IF(pay_type=2, pay_amount, 0)) est_pay', false);

它将阻止 CI 添加 ``。

看看文档：http://www.codeigniter.com/user_guide/database/active_record.html#select

$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 with backticks. This is useful if you need a compound select statement.

Answer 2

使用这个

$summ = $this->db->query("SELECT SUM(column) FROM 
table WHERE columnid > '0' ")->result_array();
echo '<br>summ=>'.$summ[0]['SUM(answer)'];

Mysql 在 codeigniter 中查询求和查询

Mysql query sum query in codeigniter

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sql

activerecord

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