如何在Codeigniter活动记录中编写sql子查询？

Question

这是在选择子查询和联接子查询中。 查询如下。

SELECT t1.BranchId,t1.BranchName,FORMAT(TotalRevenue/total_trans,2) AS Average,t1.ReadingDate 
    from (SELECT br.BranchName,
    count(nooftrans)as total_trans,zf.BranchId,ReadingDate,zf.zread_id 
    FROM `ospos_zreads_pdf` zf , ospos_branches br,ospos_zreads_pdf_activity_status zpf 
    WHERE br.BranchId = zf.BranchId and zf.zread_id=zpf.zread_id and ReadingDate >= DATE_SUB(CURDATE( ), INTERVAL 1 MONTH) and zpf.zreadactivity='Sales Transaction'
    group by zf.BranchId)t1 
    join (SELECT br.BranchName,sum(TotalRevenue)as TotalRevenue,zf.BranchId,zread_id,ReadingDate 
    FROM `ospos_zreads_pdf` zf , ospos_branches br
    WHERE br.BranchId = zf.BranchId and ReadingDate >= DATE_SUB(CURDATE( ), INTERVAL 1 MONTH) 
    group by zf.BranchId)t2 on t1.zread_id=t2.zread_id 

Answer 1

您可以使用第二个参数来禁用某些数据库方法的保护：

$this->db->select('id, title, (SELECT COUNT(*) FROM other) as count', FALSE)

文档中的更多信息： http : //www.codeigniter.com/user_guide/database/query_builder.html