Question

我想获取所选类别的category_id并将其传递给子类别的下一个查询，以便下一个组合框将根据所选类别包含子类别。你能帮我做一下吗？这是我的javascript，php和html代码。

public class WinAPI
{
    [DllImport("ntdll.dll", SetLastError = true)]
    public static extern IntPtr NtQueryInformationFile(IntPtr fileHandle, ref IO_STATUS_BLOCK IoStatusBlock, IntPtr pInfoBlock, uint length, FILE_INFORMATION_CLASS fileInformation);

    public struct IO_STATUS_BLOCK
    {
        uint status;
        ulong information;
    }
    public struct _FILE_INTERNAL_INFORMATION
    {
        public ulong IndexNumber;
    }

    // Abbreviated, there are more values than shown
    public enum FILE_INFORMATION_CLASS
    {
        FileDirectoryInformation = 1,     // 1
        FileFullDirectoryInformation,     // 2
        FileBothDirectoryInformation,     // 3
        FileBasicInformation,         // 4
        FileStandardInformation,      // 5
        FileInternalInformation      // 6
    }

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern bool GetFileInformationByHandle(IntPtr hFile, out BY_HANDLE_FILE_INFORMATION lpFileInformation);

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern IntPtr OpenFileById(IntPtr hFile, FILE_ID_DESCRIPTOR lpFileID, uint dwDesiredAccess, uint dwShareMode, uint dwFlagas);

    [StructLayout(LayoutKind.Explicit)]
    public struct FILE_ID_DESCRIPTOR
    {
        [FieldOffset(0)] public uint dwSize;
        [FieldOffset(4)] public FILE_ID_TYPE type;
       // [FieldOffset(8)] public Guid guid;
        [FieldOffset(8)] public long FileReferenceNumber;
    }

    public enum FILE_ID_TYPE
    {
        FileIdType = 0,
        ObjectIdType = 1,
        ExtendedFileIdType = 2,
        MaximumFileIdType
    };

    public struct BY_HANDLE_FILE_INFORMATION
    {
        public uint FileAttributes;
        public FILETIME CreationTime;
        public FILETIME LastAccessTime;
        public FILETIME LastWriteTime;
        public uint VolumeSerialNumber;
        public uint FileSizeHigh;
        public uint FileSizeLow;
        public uint NumberOfLinks;
        public uint FileIndexHigh;
        public uint FileIndexLow;
    }
}

public class File_Handle
{

    public ulong Get_Index()
    {
        WinAPI.BY_HANDLE_FILE_INFORMATION objectFileInfo = new WinAPI.BY_HANDLE_FILE_INFORMATION();

        FileInfo fi = new FileInfo(@"D:\Test\Testfile.txt");
        FileStream fs = fi.Open(FileMode.Open, FileAccess.Read, FileShare.ReadWrite);

        WinAPI.GetFileInformationByHandle(fs.Handle, out objectFileInfo);

        fs.Close();

        ulong fileIndex = ((ulong)objectFileInfo.FileIndexHigh << 32) + (ulong)objectFileInfo.FileIndexLow;

        return fileIndex;
    }

    public string Retrieve_File(ulong Index)
    {
        // WinAPI.BY_HANDLE_FILE_INFORMATION objectFileInfo = new WinAPI.BY_HANDLE_FILE_INFORMATION();
        // WinAPI.FILE_ID_DESCRIPTOR Descriptor = new WinAPI.FILE_ID_DESCRIPTOR { dwSize = sizeof(uint) + sizeof(WinAPI.FILE_ID_TYPE) + sizeof(long), type = WinAPI.FILE_ID_TYPE.FileIdType, FileReferenceNumber = (long)Index };
        WinAPI.FILE_ID_DESCRIPTOR Descriptor = new WinAPI.FILE_ID_DESCRIPTOR { dwSize = 100, type = WinAPI.FILE_ID_TYPE.FileIdType, FileReferenceNumber = (long)Index };

        FileInfo fi = new FileInfo(@"D:\Test\TestfileRef.txt");
        FileStream fs = fi.Open(FileMode.Open, FileAccess.Read, FileShare.ReadWrite);

        //FileStream wf = new FileStream(WinAPI.OpenFileById(fs.Handle, Descriptor, 0, 4, 0x08000000), FileAccess.ReadWrite);
        FileStream wf = new FileStream(WinAPI.OpenFileById(fs.Handle, Descriptor, 0, 0, 0x08000000), FileAccess.ReadWrite);

        WinAPI.BY_HANDLE_FILE_INFORMATION objectFileInfo = new WinAPI.BY_HANDLE_FILE_INFORMATION();
        WinAPI.GetFileInformationByHandle(wf.Handle, out objectFileInfo);
        fs.Close();

        wf.Close();

        return "Dummy";

    }
}

Answer 1

将此行编辑为：

$sql_row = mysqli_query($mysqli,"SELECT * from subcategories where category_id='".$_REQUEST['cat_id']."'");

提供$_REQUEST['cat_id']有一个值，它现在应该正确进入查询。

Answer 2

尝试删除$ _REQUEST周围的单引号。可能是DB上的列类型是int。请尝试以下代码。

      <?php
       $cat_id=$_REQUEST['cat_id'];
       $sql_row = mysqli_query($mysqli,"SELECT * from subcategories where category_id=$cat_id");

从一个组合框获取所选项目的ID到另一个组合框

2 个答案: