Question

我有一些关于mysql的数据，其中用户注册了各个区域的数据。现在我需要在区域的基础上对它们进行分组并将它们呈现在图表上。我从谷歌图表得到了反对。我的问题是如何将数据组分组。

示例：

user1 district1
user2 district2
user3 district1
user4 district1
user5 district2

现在我需要以下数据：

district1=>3
district2=>2

从MySql检索数据。任何人都可以帮助PHP代码或任何SQL查询来检索这样的数据，这样我就可以在js上传递对象以形成图形。

Answer 1

您需要从数据库中选择分区和用户数，然后按地区分组：

SELECT COUNT(user),district FROM yourtable GROUP BY district;

Answer 2

这应该有用（当然你需要根据需要调整列名和表名）：

    $('input[type=file]#imagencabecera').change(function(){
    var file = (this.files[0].name).toString();
    var type = (this.files[0].type).toString();
    var reader = new FileReader();
    console.log(type);

    $('#file-info').text('');
    $('#file-info').text(file);

    reader.onload = function (e){
        $('#filepreview img').attr('src', e.target.result);
    }

    reader.readAsDataURL(this.files[0]);
});

function checkFileType(file){
    if (window.FileReader && window.Blob)
    // All the File APIs are supported. Si soporta HTML5 FileReader y Blob
    {
        var slice = file.slice(0,4);      // Get the first 4 bytes of a file
        var reader = new FileReader();    // Create instance of file reader. It is asynchronous!
        reader.readAsArrayBuffer(slice);  // Read the chunk file and return to blob

        reader.onload = function(e) {
            var buffer = reader.result;          // The result ArrayBuffer
            var view = new DataView(buffer);     // Get access to the result bytes
            var signature = view.getUint32(0, false).toString(16);  // Read 4 bytes, big-endian，return hex string

            switch(signature) // Every file has a unique signature, we can collect them and create a data lib
            {                      
                case "89504e47": file.verified_type = "image/png"; break;
                case "47494638": file.verified_type = "image/gif"; break;
                case "FFd8FFe0": file.verified_type = "image/jpeg"; break;
                case "FFd8FFe1": file.verified_type = "image/jpeg"; break;
                case "FFd8FFe2": file.verified_type = "image/jpeg"; break;                  
                case "FFd8FFe3": file.verified_type = "image/jpeg"; break;
                case "FFd8FFe8": file.verified_type = "image/jpeg"; break;
                default: file.verified_type = 0;
            }
        }

    }
    else
    // File and Blob are not supported
    {

    }
}

在php上分组数据

2 个答案: