Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>The <code>Extents</code> field is a variable length array inlined in a struct. The actual struct will have <code>ExtentCount</code> elements. You cannot use a Delphi dynamic array here. In fact you can never use a Delphi dynamic array in interop.</p> <p>So, declare it as <code>array [0..0]</code> just as the C code does. In order to access it you'll need to disable range checking. An actual instance of this record will have valid data in indices <code>0..ExtentCount-1</code>.</p> <p>For your integral types, map <code>DWORD</code> in C to <code>DWORD</code> in Delphi. And <code>LARGE_INTEGER</code> in C to <code>LARGE_INTEGER</code> in Delphi. Neither of those are the same as Delphi <code>Integer</code>. The former is unsigned, and the latter is 64 bits wide.</p> <pre><code>PRetrievalPointersBuffer = ^TRetrievalPointersBuffer; TRetrievalPointersBuffer = record ExtentCount: DWORD; StartingVcn: LARGE_INTEGER; Extents: array [0..0] of record NextVcn: LARGE_INTEGER; Lcn: LARGE_INTEGER; end; end; </code></pre> <p>The <code>LARGE_INTEGER</code> type is rather awkward to work with. You may prefer to declare those fields as <code>Int64</code> instead.</p> <hr> <p>This type of struct is invariably heap allocated. The heap allocation code has to work out the size needed to fit <code>ElementCount</code> items in the variable length array. If you are allocating the buffer then you'll need the inner record in a separately defined type so that you can conveniently name it to pass to <code>SizeOf</code>. If the API allocates then you are fine as above.</p>
    singulars
    1. This table or related slice is empty.
    1. POHow to translate RETRIEVAL_POINTERS_BUFFER structure to Delphi?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USDavid Heffernan
    1. USDavid Heffernan
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POHow to translate RETRIEVAL_POINTERS_BUFFER structure to Delphi?
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. CO+1, especially for your edit. I almost always give inner records a separately defined type. It makes a lot of things very easy. With the introduction of record methods, I'd add a method on the `TRetrievalPointersBuffer` type that calculates the total size for a given `ExtentCount`.
      singulars
      1. PO
      1. USJeroen Wiert Pluimers
    2. CO@jeroen In this was I'd define the inner type inside the outer record.
      singulars
      1. PO
      1. USDavid Heffernan
    3. COWhen you know the high bound of the array you can have it in the stack by declaring the array accordingly. Not for this specific case, but suppose you have `WCHAR Name[1]` and you know that it is at most 255 characters, then you can define the field as `Name: WCHAR[0..254]`.
      singulars
      1. PO
      1. USSertac Akyuz
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload