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SQLDescribeColW

関数
結果セット列の名前や型などの属性を取得する(Unicode)。
DLLODBC32.dll文字セットUnicode (-W)呼出規約winapi

シグネチャ

// ODBC32.dll  (Unicode / -W)
#include <windows.h>

SHORT SQLDescribeColW(
    void* hstmt,
    WORD icol,
    WORD* szColName,   // optional
    SHORT cchColNameMax,
    SHORT* pcchColName,   // optional
    SHORT* pfSqlType,   // optional
    DWORD* pcbColDef,   // optional
    SHORT* pibScale,   // optional
    SHORT* pfNullable   // optional
);

パラメーター

名前型方向説明
hstmtvoid*inout対象のステートメントハンドル。結果列のメタデータを記述する。
icolWORDin記述する列番号。1始まりで指定する。
szColNameWORD*outoptional列名を受け取るバッファ。Unicode文字列。
cchColNameMaxSHORTinszColNameバッファの文字数長。
pcchColNameSHORT*outoptional列名の実際の文字数を受け取るポインタ。NULL可。
pfSqlTypeSHORT*outoptional列のSQLデータ型を受け取るポインタ。
pcbColDefDWORD*outoptional列のサイズ(精度)を受け取るポインタ。
pibScaleSHORT*outoptional小数点以下桁数(スケール)を受け取るポインタ。
pfNullableSHORT*outoptionalNULL許容フラグを受け取るポインタ。SQL_NULLABLE等。

戻り値の型: SHORT

各言語での呼び出し定義

// ODBC32.dll  (Unicode / -W)
#include <windows.h>

SHORT SQLDescribeColW(
    void* hstmt,
    WORD icol,
    WORD* szColName,   // optional
    SHORT cchColNameMax,
    SHORT* pcchColName,   // optional
    SHORT* pfSqlType,   // optional
    DWORD* pcbColDef,   // optional
    SHORT* pibScale,   // optional
    SHORT* pfNullable   // optional
);
[DllImport("ODBC32.dll", CharSet = CharSet.Unicode, ExactSpelling = true)]
static extern short SQLDescribeColW(
    IntPtr hstmt,   // void* in/out
    ushort icol,   // WORD
    IntPtr szColName,   // WORD* optional, out
    short cchColNameMax,   // SHORT
    IntPtr pcchColName,   // SHORT* optional, out
    IntPtr pfSqlType,   // SHORT* optional, out
    IntPtr pcbColDef,   // DWORD* optional, out
    IntPtr pibScale,   // SHORT* optional, out
    IntPtr pfNullable   // SHORT* optional, out
);
<DllImport("ODBC32.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function SQLDescribeColW(
    hstmt As IntPtr,   ' void* in/out
    icol As UShort,   ' WORD
    szColName As IntPtr,   ' WORD* optional, out
    cchColNameMax As Short,   ' SHORT
    pcchColName As IntPtr,   ' SHORT* optional, out
    pfSqlType As IntPtr,   ' SHORT* optional, out
    pcbColDef As IntPtr,   ' DWORD* optional, out
    pibScale As IntPtr,   ' SHORT* optional, out
    pfNullable As IntPtr   ' SHORT* optional, out
) As Short
End Function
' hstmt : void* in/out
' icol : WORD
' szColName : WORD* optional, out
' cchColNameMax : SHORT
' pcchColName : SHORT* optional, out
' pfSqlType : SHORT* optional, out
' pcbColDef : DWORD* optional, out
' pibScale : SHORT* optional, out
' pfNullable : SHORT* optional, out
Declare PtrSafe Function SQLDescribeColW Lib "odbc32" ( _
    ByVal hstmt As LongPtr, _
    ByVal icol As Integer, _
    ByVal szColName As LongPtr, _
    ByVal cchColNameMax As Integer, _
    ByVal pcchColName As LongPtr, _
    ByVal pfSqlType As LongPtr, _
    ByVal pcbColDef As LongPtr, _
    ByVal pibScale As LongPtr, _
    ByVal pfNullable As LongPtr) As Integer
' Unicode(W): 文字列は ByVal As LongPtr とし StrPtr(unicodeStr) を渡す
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。
import ctypes
from ctypes import wintypes

SQLDescribeColW = ctypes.windll.odbc32.SQLDescribeColW
SQLDescribeColW.restype = ctypes.c_short
SQLDescribeColW.argtypes = [
    ctypes.POINTER(None),  # hstmt : void* in/out
    ctypes.c_ushort,  # icol : WORD
    ctypes.POINTER(ctypes.c_ushort),  # szColName : WORD* optional, out
    ctypes.c_short,  # cchColNameMax : SHORT
    ctypes.POINTER(ctypes.c_short),  # pcchColName : SHORT* optional, out
    ctypes.POINTER(ctypes.c_short),  # pfSqlType : SHORT* optional, out
    ctypes.POINTER(wintypes.DWORD),  # pcbColDef : DWORD* optional, out
    ctypes.POINTER(ctypes.c_short),  # pibScale : SHORT* optional, out
    ctypes.POINTER(ctypes.c_short),  # pfNullable : SHORT* optional, out
]
require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('ODBC32.dll')
SQLDescribeColW = Fiddle::Function.new(
  lib['SQLDescribeColW'],
  [
    Fiddle::TYPE_VOIDP,  # hstmt : void* in/out
    -Fiddle::TYPE_SHORT,  # icol : WORD
    Fiddle::TYPE_VOIDP,  # szColName : WORD* optional, out
    Fiddle::TYPE_SHORT,  # cchColNameMax : SHORT
    Fiddle::TYPE_VOIDP,  # pcchColName : SHORT* optional, out
    Fiddle::TYPE_VOIDP,  # pfSqlType : SHORT* optional, out
    Fiddle::TYPE_VOIDP,  # pcbColDef : DWORD* optional, out
    Fiddle::TYPE_VOIDP,  # pibScale : SHORT* optional, out
    Fiddle::TYPE_VOIDP,  # pfNullable : SHORT* optional, out
  ],
  Fiddle::TYPE_SHORT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"
#[link(name = "odbc32")]
extern "system" {
    fn SQLDescribeColW(
        hstmt: *mut (),  // void* in/out
        icol: u16,  // WORD
        szColName: *mut u16,  // WORD* optional, out
        cchColNameMax: i16,  // SHORT
        pcchColName: *mut i16,  // SHORT* optional, out
        pfSqlType: *mut i16,  // SHORT* optional, out
        pcbColDef: *mut u32,  // DWORD* optional, out
        pibScale: *mut i16,  // SHORT* optional, out
        pfNullable: *mut i16  // SHORT* optional, out
    ) -> i16;
}
// crates: windows-sys provides ready-made bindings for this API.
$sig = @"
[DllImport("ODBC32.dll", CharSet = CharSet.Unicode)]
public static extern short SQLDescribeColW(IntPtr hstmt, ushort icol, IntPtr szColName, short cchColNameMax, IntPtr pcchColName, IntPtr pfSqlType, IntPtr pcbColDef, IntPtr pibScale, IntPtr pfNullable);
"@
$api = Add-Type -MemberDefinition $sig -Name 'ODBC32_SQLDescribeColW' -Namespace Win32 -PassThru
# $api::SQLDescribeColW(hstmt, icol, szColName, cchColNameMax, pcchColName, pfSqlType, pcbColDef, pibScale, pfNullable)
#uselib "ODBC32.dll"
#func global SQLDescribeColW "SQLDescribeColW" wptr, wptr, wptr, wptr, wptr, wptr, wptr, wptr, wptr
; SQLDescribeColW hstmt, icol, varptr(szColName), cchColNameMax, varptr(pcchColName), varptr(pfSqlType), varptr(pcbColDef), varptr(pibScale), varptr(pfNullable)   ; 戻り値は stat
; hstmt : void* in/out -> "wptr"
; icol : WORD -> "wptr"
; szColName : WORD* optional, out -> "wptr"
; cchColNameMax : SHORT -> "wptr"
; pcchColName : SHORT* optional, out -> "wptr"
; pfSqlType : SHORT* optional, out -> "wptr"
; pcbColDef : DWORD* optional, out -> "wptr"
; pibScale : SHORT* optional, out -> "wptr"
; pfNullable : SHORT* optional, out -> "wptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。
出力引数: 
#uselib "ODBC32.dll"
#cfunc global SQLDescribeColW "SQLDescribeColW" sptr, int, var, int, var, var, var, var, var
; res = SQLDescribeColW(hstmt, icol, szColName, cchColNameMax, pcchColName, pfSqlType, pcbColDef, pibScale, pfNullable)
; hstmt : void* in/out -> "sptr"
; icol : WORD -> "int"
; szColName : WORD* optional, out -> "var"
; cchColNameMax : SHORT -> "int"
; pcchColName : SHORT* optional, out -> "var"
; pfSqlType : SHORT* optional, out -> "var"
; pcbColDef : DWORD* optional, out -> "var"
; pibScale : SHORT* optional, out -> "var"
; pfNullable : SHORT* optional, out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。
出力引数: 
; SHORT SQLDescribeColW(void* hstmt, WORD icol, WORD* szColName, SHORT cchColNameMax, SHORT* pcchColName, SHORT* pfSqlType, DWORD* pcbColDef, SHORT* pibScale, SHORT* pfNullable)
#uselib "ODBC32.dll"
#cfunc global SQLDescribeColW "SQLDescribeColW" intptr, int, var, int, var, var, var, var, var
; res = SQLDescribeColW(hstmt, icol, szColName, cchColNameMax, pcchColName, pfSqlType, pcbColDef, pibScale, pfNullable)
; hstmt : void* in/out -> "intptr"
; icol : WORD -> "int"
; szColName : WORD* optional, out -> "var"
; cchColNameMax : SHORT -> "int"
; pcchColName : SHORT* optional, out -> "var"
; pfSqlType : SHORT* optional, out -> "var"
; pcbColDef : DWORD* optional, out -> "var"
; pibScale : SHORT* optional, out -> "var"
; pfNullable : SHORT* optional, out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。
import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	odbc32 = windows.NewLazySystemDLL("ODBC32.dll")
	procSQLDescribeColW = odbc32.NewProc("SQLDescribeColW")
)

// hstmt (void* in/out), icol (WORD), szColName (WORD* optional, out), cchColNameMax (SHORT), pcchColName (SHORT* optional, out), pfSqlType (SHORT* optional, out), pcbColDef (DWORD* optional, out), pibScale (SHORT* optional, out), pfNullable (SHORT* optional, out)
r1, _, err := procSQLDescribeColW.Call(
	uintptr(hstmt),
	uintptr(icol),
	uintptr(szColName),
	uintptr(cchColNameMax),
	uintptr(pcchColName),
	uintptr(pfSqlType),
	uintptr(pcbColDef),
	uintptr(pibScale),
	uintptr(pfNullable),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // SHORT
function SQLDescribeColW(
  hstmt: Pointer;   // void* in/out
  icol: Word;   // WORD
  szColName: Pointer;   // WORD* optional, out
  cchColNameMax: Smallint;   // SHORT
  pcchColName: Pointer;   // SHORT* optional, out
  pfSqlType: Pointer;   // SHORT* optional, out
  pcbColDef: Pointer;   // DWORD* optional, out
  pibScale: Pointer;   // SHORT* optional, out
  pfNullable: Pointer   // SHORT* optional, out
): Smallint; stdcall;
  external 'ODBC32.dll' name 'SQLDescribeColW';
result := DllCall("ODBC32\SQLDescribeColW"
    , "Ptr", hstmt   ; void* in/out
    , "UShort", icol   ; WORD
    , "Ptr", szColName   ; WORD* optional, out
    , "Short", cchColNameMax   ; SHORT
    , "Ptr", pcchColName   ; SHORT* optional, out
    , "Ptr", pfSqlType   ; SHORT* optional, out
    , "Ptr", pcbColDef   ; DWORD* optional, out
    , "Ptr", pibScale   ; SHORT* optional, out
    , "Ptr", pfNullable   ; SHORT* optional, out
    , "Short")   ; return: SHORT
●SQLDescribeColW(hstmt, icol, szColName, cchColNameMax, pcchColName, pfSqlType, pcbColDef, pibScale, pfNullable) = DLL("ODBC32.dll", "int SQLDescribeColW(void*, int, void*, int, void*, void*, void*, void*, void*)")
# 呼び出し: SQLDescribeColW(hstmt, icol, szColName, cchColNameMax, pcchColName, pfSqlType, pcbColDef, pibScale, pfNullable)
# hstmt : void* in/out -> "void*"
# icol : WORD -> "int"
# szColName : WORD* optional, out -> "void*"
# cchColNameMax : SHORT -> "int"
# pcchColName : SHORT* optional, out -> "void*"
# pfSqlType : SHORT* optional, out -> "void*"
# pcbColDef : DWORD* optional, out -> "void*"
# pibScale : SHORT* optional, out -> "void*"
# pfNullable : SHORT* optional, out -> "void*"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。
# ※-W(Unicode)関数。なでしこ1はANSIのため -A 版の利用を推奨。
const std = @import("std");

extern "odbc32" fn SQLDescribeColW(
    hstmt: ?*anyopaque, // void* in/out
    icol: u16, // WORD
    szColName: [*c]u16, // WORD* optional, out
    cchColNameMax: i16, // SHORT
    pcchColName: [*c]i16, // SHORT* optional, out
    pfSqlType: [*c]i16, // SHORT* optional, out
    pcbColDef: [*c]u32, // DWORD* optional, out
    pibScale: [*c]i16, // SHORT* optional, out
    pfNullable: [*c]i16 // SHORT* optional, out
) callconv(std.os.windows.WINAPI) i16;
// Unicode(-W): UTF-16LE のヌル終端バッファ([*c]const u16)を渡す。
proc SQLDescribeColW(
    hstmt: pointer,  # void* in/out
    icol: uint16,  # WORD
    szColName: ptr uint16,  # WORD* optional, out
    cchColNameMax: int16,  # SHORT
    pcchColName: ptr int16,  # SHORT* optional, out
    pfSqlType: ptr int16,  # SHORT* optional, out
    pcbColDef: ptr uint32,  # DWORD* optional, out
    pibScale: ptr int16,  # SHORT* optional, out
    pfNullable: ptr int16  # SHORT* optional, out
): int16 {.importc: "SQLDescribeColW", stdcall, dynlib: "ODBC32.dll".}
# Unicode(-W): WideCString は newWideCString("...") で生成。
pragma(lib, "odbc32");
extern(Windows)
short SQLDescribeColW(
    void* hstmt,   // void* in/out
    ushort icol,   // WORD
    ushort* szColName,   // WORD* optional, out
    short cchColNameMax,   // SHORT
    short* pcchColName,   // SHORT* optional, out
    short* pfSqlType,   // SHORT* optional, out
    uint* pcbColDef,   // DWORD* optional, out
    short* pibScale,   // SHORT* optional, out
    short* pfNullable   // SHORT* optional, out
);
ccall((:SQLDescribeColW, "ODBC32.dll"), stdcall, Int16,
      (Ptr{Cvoid}, UInt16, Ptr{UInt16}, Int16, Ptr{Int16}, Ptr{Int16}, Ptr{UInt32}, Ptr{Int16}, Ptr{Int16}),
      hstmt, icol, szColName, cchColNameMax, pcchColName, pfSqlType, pcbColDef, pibScale, pfNullable)
# hstmt : void* in/out -> Ptr{Cvoid}
# icol : WORD -> UInt16
# szColName : WORD* optional, out -> Ptr{UInt16}
# cchColNameMax : SHORT -> Int16
# pcchColName : SHORT* optional, out -> Ptr{Int16}
# pfSqlType : SHORT* optional, out -> Ptr{Int16}
# pcbColDef : DWORD* optional, out -> Ptr{UInt32}
# pibScale : SHORT* optional, out -> Ptr{Int16}
# pfNullable : SHORT* optional, out -> Ptr{Int16}
# stdcall は 32bit のみ意味を持つ(x64 では無視)。
# Unicode(-W): Cwstring には transcode(UInt16, "...") 等で UTF-16 を渡す。
local ffi = require("ffi")
ffi.cdef[[
int16_t SQLDescribeColW(
    void* hstmt,
    uint16_t icol,
    uint16_t* szColName,
    int16_t cchColNameMax,
    int16_t* pcchColName,
    int16_t* pfSqlType,
    uint32_t* pcbColDef,
    int16_t* pibScale,
    int16_t* pfNullable);
]]
local odbc32 = ffi.load("odbc32")
-- odbc32.SQLDescribeColW(hstmt, icol, szColName, cchColNameMax, pcchColName, pfSqlType, pcbColDef, pibScale, pfNullable)
-- hstmt : void* in/out
-- icol : WORD
-- szColName : WORD* optional, out
-- cchColNameMax : SHORT
-- pcchColName : SHORT* optional, out
-- pfSqlType : SHORT* optional, out
-- pcbColDef : DWORD* optional, out
-- pibScale : SHORT* optional, out
-- pfNullable : SHORT* optional, out
-- 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。
-- Unicode(-W): uint16_t* には UTF-16LE のバッファ(ffi.new("uint16_t[?]", ...))を渡す。
const koffi = require('koffi');
const lib = koffi.load('ODBC32.dll');
const SQLDescribeColW = lib.func('__stdcall', 'SQLDescribeColW', 'int16_t', ['void *', 'uint16_t', 'uint16_t *', 'int16_t', 'int16_t *', 'int16_t *', 'uint32_t *', 'int16_t *', 'int16_t *']);
// SQLDescribeColW(hstmt, icol, szColName, cchColNameMax, pcchColName, pfSqlType, pcbColDef, pibScale, pfNullable)
// hstmt : void* in/out -> 'void *'
// icol : WORD -> 'uint16_t'
// szColName : WORD* optional, out -> 'uint16_t *'
// cchColNameMax : SHORT -> 'int16_t'
// pcchColName : SHORT* optional, out -> 'int16_t *'
// pfSqlType : SHORT* optional, out -> 'int16_t *'
// pcbColDef : DWORD* optional, out -> 'uint32_t *'
// pibScale : SHORT* optional, out -> 'int16_t *'
// pfNullable : SHORT* optional, out -> 'int16_t *'
// 出力ポインタは koffi.out(...) で包む。構造体は koffi.struct で定義。
const lib = Deno.dlopen("ODBC32.dll", {
  SQLDescribeColW: { parameters: ["pointer", "u16", "pointer", "i16", "pointer", "pointer", "pointer", "pointer", "pointer"], result: "i16" },
});
// lib.symbols.SQLDescribeColW(hstmt, icol, szColName, cchColNameMax, pcchColName, pfSqlType, pcbColDef, pibScale, pfNullable)
// hstmt : void* in/out -> "pointer"
// icol : WORD -> "u16"
// szColName : WORD* optional, out -> "pointer"
// cchColNameMax : SHORT -> "i16"
// pcchColName : SHORT* optional, out -> "pointer"
// pfSqlType : SHORT* optional, out -> "pointer"
// pcbColDef : DWORD* optional, out -> "pointer"
// pibScale : SHORT* optional, out -> "pointer"
// pfNullable : SHORT* optional, out -> "pointer"
// 文字列は "buffer"。Unicode(-W) は new TextEncoder() ではなく UTF-16LE のバイト列(末尾に \x00\x00)を Uint8Array で渡す。
// 値渡し構造体は { struct: [ ...field types... ] } を使用。
<?php
$ffi = FFI::cdef(<<<C
int16_t SQLDescribeColW(
    void* hstmt,
    uint16_t icol,
    uint16_t* szColName,
    int16_t cchColNameMax,
    int16_t* pcchColName,
    int16_t* pfSqlType,
    uint32_t* pcbColDef,
    int16_t* pibScale,
    int16_t* pfNullable);
C, "ODBC32.dll");
// $ffi->SQLDescribeColW(hstmt, icol, szColName, cchColNameMax, pcchColName, pfSqlType, pcbColDef, pibScale, pfNullable);
// hstmt : void* in/out
// icol : WORD
// szColName : WORD* optional, out
// cchColNameMax : SHORT
// pcchColName : SHORT* optional, out
// pfSqlType : SHORT* optional, out
// pcbColDef : DWORD* optional, out
// pibScale : SHORT* optional, out
// pfNullable : SHORT* optional, out
// 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。
// WINAPI(stdcall): x64 では呼出規約が統一されるため問題なし。x86 では __stdcall 対応のラッパが必要な場合あり。
import com.sun.jna.*;
import com.sun.jna.ptr.*;
import com.sun.jna.win32.StdCallLibrary;
import com.sun.jna.win32.W32APIOptions;

public interface Odbc32 extends StdCallLibrary {
    Odbc32 INSTANCE = Native.load("odbc32", Odbc32.class, W32APIOptions.UNICODE_OPTIONS);
    short SQLDescribeColW(
        Pointer hstmt,   // void* in/out
        short icol,   // WORD
        ShortByReference szColName,   // WORD* optional, out
        short cchColNameMax,   // SHORT
        ShortByReference pcchColName,   // SHORT* optional, out
        ShortByReference pfSqlType,   // SHORT* optional, out
        IntByReference pcbColDef,   // DWORD* optional, out
        ShortByReference pibScale,   // SHORT* optional, out
        ShortByReference pfNullable   // SHORT* optional, out
    );
}
// Unicode(-W): WString(入力)/char[](出力)で UTF-16 をマーシャリング。
@[Link("odbc32")]
lib LibODBC32
  fun SQLDescribeColW = SQLDescribeColW(
    hstmt : Void*,   # void* in/out
    icol : UInt16,   # WORD
    szColName : UInt16*,   # WORD* optional, out
    cchColNameMax : Int16,   # SHORT
    pcchColName : Int16*,   # SHORT* optional, out
    pfSqlType : Int16*,   # SHORT* optional, out
    pcbColDef : UInt32*,   # DWORD* optional, out
    pibScale : Int16*,   # SHORT* optional, out
    pfNullable : Int16*   # SHORT* optional, out
  ) : Int16
end
# 構造体/GUID/enum は lib 内に対応する型定義が必要。
# 呼出規約: x64 は規約統一のため OK。x86(32bit)は WINAPI=stdcall だが Crystal の fun に stdcall 付与構文がなく非対応。
import 'dart:ffi';
import 'package:ffi/ffi.dart';

typedef SQLDescribeColWNative = Int16 Function(Pointer<Void>, Uint16, Pointer<Uint16>, Int16, Pointer<Int16>, Pointer<Int16>, Pointer<Uint32>, Pointer<Int16>, Pointer<Int16>);
typedef SQLDescribeColWDart = int Function(Pointer<Void>, int, Pointer<Uint16>, int, Pointer<Int16>, Pointer<Int16>, Pointer<Uint32>, Pointer<Int16>, Pointer<Int16>);
final SQLDescribeColW = DynamicLibrary.open('ODBC32.dll')
    .lookupFunction<SQLDescribeColWNative, SQLDescribeColWDart>('SQLDescribeColW');
// hstmt : void* in/out -> Pointer<Void>
// icol : WORD -> Uint16
// szColName : WORD* optional, out -> Pointer<Uint16>
// cchColNameMax : SHORT -> Int16
// pcchColName : SHORT* optional, out -> Pointer<Int16>
// pfSqlType : SHORT* optional, out -> Pointer<Int16>
// pcbColDef : DWORD* optional, out -> Pointer<Uint32>
// pibScale : SHORT* optional, out -> Pointer<Int16>
// pfNullable : SHORT* optional, out -> Pointer<Int16>
// 文字列は package:ffi の "...".toNativeUtf16()/toNativeUtf8() で変換。
{$mode objfpc}{$H+}
function SQLDescribeColW(
  hstmt: Pointer;   // void* in/out
  icol: Word;   // WORD
  szColName: Pointer;   // WORD* optional, out
  cchColNameMax: Smallint;   // SHORT
  pcchColName: Pointer;   // SHORT* optional, out
  pfSqlType: Pointer;   // SHORT* optional, out
  pcbColDef: Pointer;   // DWORD* optional, out
  pibScale: Pointer;   // SHORT* optional, out
  pfNullable: Pointer   // SHORT* optional, out
): Smallint; stdcall;
  external 'ODBC32.dll' name 'SQLDescribeColW';
import Foreign
import Foreign.C.Types
import Foreign.C.String

foreign import stdcall safe "SQLDescribeColW"
  c_SQLDescribeColW :: Ptr () -> Word16 -> Ptr Word16 -> Int16 -> Ptr Int16 -> Ptr Int16 -> Ptr Word32 -> Ptr Int16 -> Ptr Int16 -> IO Int16
-- hstmt : void* in/out -> Ptr ()
-- icol : WORD -> Word16
-- szColName : WORD* optional, out -> Ptr Word16
-- cchColNameMax : SHORT -> Int16
-- pcchColName : SHORT* optional, out -> Ptr Int16
-- pfSqlType : SHORT* optional, out -> Ptr Int16
-- pcbColDef : DWORD* optional, out -> Ptr Word32
-- pibScale : SHORT* optional, out -> Ptr Int16
-- pfNullable : SHORT* optional, out -> Ptr Int16
-- 要 GHC(Windows)。stdcall は x64 では ccall として扱われる。ブロックする API は safe 呼び出し推奨。
open Ctypes
open Foreign

let sqldescribecolw =
  foreign "SQLDescribeColW"
    ((ptr void) @-> uint16_t @-> (ptr uint16_t) @-> int16_t @-> (ptr int16_t) @-> (ptr int16_t) @-> (ptr uint32_t) @-> (ptr int16_t) @-> (ptr int16_t) @-> returning int16_t)
(* hstmt : void* in/out -> (ptr void) *)
(* icol : WORD -> uint16_t *)
(* szColName : WORD* optional, out -> (ptr uint16_t) *)
(* cchColNameMax : SHORT -> int16_t *)
(* pcchColName : SHORT* optional, out -> (ptr int16_t) *)
(* pfSqlType : SHORT* optional, out -> (ptr int16_t) *)
(* pcbColDef : DWORD* optional, out -> (ptr uint32_t) *)
(* pibScale : SHORT* optional, out -> (ptr int16_t) *)
(* pfNullable : SHORT* optional, out -> (ptr int16_t) *)
(* foreign は cdecl 前提。x64 Windows では WINAPI と一致。構造体は ctypes structure を定義のこと。 *)
(cffi:define-foreign-library odbc32 (t "ODBC32.dll"))
(cffi:use-foreign-library odbc32)

(cffi:defcfun ("SQLDescribeColW" sqldescribe-col-w :convention :stdcall) :int16
  (hstmt :pointer)   ; void* in/out
  (icol :uint16)   ; WORD
  (sz-col-name :pointer)   ; WORD* optional, out
  (cch-col-name-max :int16)   ; SHORT
  (pcch-col-name :pointer)   ; SHORT* optional, out
  (pf-sql-type :pointer)   ; SHORT* optional, out
  (pcb-col-def :pointer)   ; DWORD* optional, out
  (pib-scale :pointer)   ; SHORT* optional, out
  (pf-nullable :pointer))   ; SHORT* optional, out
; isize/usize(INT_PTR/SIZE_T)は x64 前提で :int64/:uint64。x86 では :int32/:uint32。
use Win32::API;
my $SQLDescribeColW = Win32::API::More->new('ODBC32',
    'short SQLDescribeColW(LPVOID hstmt, WORD icol, LPVOID szColName, short cchColNameMax, LPVOID pcchColName, LPVOID pfSqlType, LPVOID pcbColDef, LPVOID pibScale, LPVOID pfNullable)');
# my $ret = $SQLDescribeColW->Call($hstmt, $icol, $szColName, $cchColNameMax, $pcchColName, $pfSqlType, $pcbColDef, $pibScale, $pfNullable);
# hstmt : void* in/out -> LPVOID
# icol : WORD -> WORD
# szColName : WORD* optional, out -> LPVOID
# cchColNameMax : SHORT -> short
# pcchColName : SHORT* optional, out -> LPVOID
# pfSqlType : SHORT* optional, out -> LPVOID
# pcbColDef : DWORD* optional, out -> LPVOID
# pibScale : SHORT* optional, out -> LPVOID
# pfNullable : SHORT* optional, out -> LPVOID
# 値渡し構造体は pack() した文字列、または Win32::API::Struct を使用。
# Unicode(-W): LPCWSTR/LPWSTR は Win32::API が UTF-16 変換を行う。

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