Question

我有以下查询

$query = $this->db->query(
        'SELECT ii.json

        FROM inventory ii
        INNER JOIN
        (
            SELECT json, MAX(id) as MAX_ID
            FROM inventory
            GROUP BY business_unit
        ) group_json ON ii.id = group_json.MAX_ID

        INNER JOIN business_units 
        ON ii.business_unit = business_units.id'
    );

    return $query->result_array();

我们不得不迁移到MSSQL测试服务器，遗憾的是语法不正确。为了避免将来这种情况，我想将其转换为CodeIgniter类型的查询。

任何人都可以告诉我这个查询在CodeIgniter中会是什么样子，我已经尝试了一些东西，但我没有得到任何接近。

Answer 1

SELECT ii.json
FROM inventory ii
INNER JOIN
(
    SELECT json, MAX(id) as MAX_ID
    FROM inventory
    GROUP BY business_unit, json    --<-- "json" needs to be in GROUP BY
) group_json                           -- Since it is in SELECT but not
ON ii.id = group_json.MAX_ID           -- contained in any aggregate function
INNER JOIN business_units 
ON ii.business_unit = business_units.id

如果你在SELECT任何其他列中使用任何聚合函数（MAX，MIN，AVG，SUM，COUNT），那么该选项中的任何聚合函数都不包含这些函数，必须进入GROUP BY您的查询的子句。

如何将命名内连接查询转换为代码点火器语法？

1 个答案: