Question

您好我遇到了如何在php中按json格式分组的问题。

这是我的代码。

$sql = "SELECT * FROM event as e 
        JOIN course as c ON e.id = c.event_id
        JOIN hold as h ON c.id = h.course_id
        GROUP By h.id";

$query = mysqli_query($con, $sql);

$data = [];
while( $row = mysqli_fetch_assoc($query) ) {

    $eInfo = new stdClass();
    $eInfo->e_info = [];

    $event = new stdClass();

    $event->e_code = $row['e_code'];
    $event->c_info = [];

    $course = new stdClass();
    $course->c_code = $row['course_code'];
    $course->h_info = [];

    $hold = new stdClass();

    $hold->h_code = $row['hold_code'];

    $course->h_info[] = $hold;

    $event->c_info[] = $course;

    $eInfo->e_info[] = $event;

    $data[] = $eInfo;

}

$json = json_encode($data, JSON_PRETTY_PRINT);
return $json

结果是：

[
{
    "e_info": [
        {
            "e_code": "e001",
            "c_info": [
                {
                    "c_code": "C001",
                    "h_info": [
                        {
                            "h_code": "h001"
                        }
                    ]
                }
            ]
        }
    ]
},
{
    "e_info": [
        {
            "e_code": "e001",
            "c_info": [
                {
                    "c_code": "C001",
                    "h_info": [
                        {
                            "h_code": "h002"
                        }
                    ]
                }
            ]
        }
    ]
},
{
    "e_info": [
        {
            "e_code": "e001",
            "c_info": [
                {
                    "c_code": "C002",
                    "h_info": [
                        {
                            "h_code": "h001"
                        }
                    ]
                }
            ]
        }
    ]
},
{
    "e_info": [
        {
            "e_code": "e001",
            "c_info": [
                {
                    "c_code": "C002",
                    "h_info": [
                        {
                            "h_code": "h002"
                        }
                    ]
                }
            ]
        }
    ]
}
]

e_code和course_code是重复的，我想将这些分组。用php作为json格式可以得到像这样的json数组吗？

[
{
    "e_info": [
        {
            "e_code": "e001",
            "c_info": [
                {
                    "c_code": "c001",
                    "h_info": [
                        {
                            "h_code": "h001"
                        },
                        {
                            "h_code": "h002"
                        }
                    ]
                },
                {
                    "c_code": "c002",
                    "h_info": [
                        {
                            "h_code": "h001"
                        },
                        {
                            "h_code": "h002"
                        }
                    ]
                }
            ]
        }
    ]
}
]

请帮帮我。谢谢。

Answer 1

您必须在GROUP BY语句中尝试使用SELECT

"SELECT * FROM tablename GROUP BY e_code, c_code";

分组通过在PHP中获取JSON格式

1 个答案: