最小代码示例（C＃）

Question

此问题是Microsoft ODBC中一系列错误的一部分   驱动程序：


ODBC driver fails to raise errors; but instead suppresses them

Reading columns out of order returns incorrect results

Cannot execute a stored procedure that is a SYNONYM


微软表示他们不会在他们的ODBC中修复这些错误   驱动程序。

短版

如果我在 SELECT 顺序中读取 uniqueidentifier 值，我会返回正确的值：

ColumnB ：（读取有效值）
ColumnC （读取有效值）

如果我读取选择顺序之外的uniqueidentifier列值，则较早的列不返回任何内容（有时是垃圾）：

ColumnC （读取有效值）
ColumnB （返回空）

我已经测试了这个：

Microsoft SQL Azure（RTM） - 12.0.2000.8
Microsoft SQL Server 2012（SP3）
Microsoft SQL Server 2008 R2（SP2）
Microsoft SQL Server 2005 - 9.00.5000.00（Intel X86）
Windows 10
Windows 7
Windows Vista

修改：提供的代码示例：

C＃（命令行应用程序）
Delphi （命令行应用程序）
Javascript （命令行cscript）
Html + Javascript （仅限Internet Explorer）

背景

使用the announcement of the deprecation of OleDb drivers，我想测试使用SQL Server的ODBC驱动程序。当我更改连接以使用其中一个SQL Server ODBC驱动程序（例如“{SQL Server}”）并执行相同的SQL语句时。

更新 - 未完成：六年后，Microsoft已announced the un-deprecation the SQL Server OLE DB driver。 （archive）

以前，Microsoft announced deprecation of the Microsoft OLE DB Provider for SQL Server是SQL Server Native Client（SNAC）的一部分。当时，当我们使用Azure SQL数据库进入云时代时，我们决定尝试为Windows本机软件开发提供更简单的开发人员故事，并尝试利用JDBC和ODBC的相似性为开发人员。但是，在随后的审核过程中，确定弃用是一个错误，因为SQL Server中的实际场景仍然依赖于OLE DB，而更改这些场景会破坏一些现有的客户场景。

考虑到这一点，我们决定取消激活OLE DB 并在2018年3月的第一季度发布新版本。

我正在发出三个固定列的查询：

SELECT
   CAST('Hello' AS varchar(max)) AS ColumnA,
   CAST('C6705EDE-CE58-4AB9-81BE-679AC1E75DE6' AS uniqueidentifier) AS ColumnB,
   CAST('2466C151-88EC-40C0-B091-25B6BD74070C' AS uniqueidentifier) AS ColumnC

这意味着有三列：

| ColumnA            | ColumnB                              | ColumnC                              |
| varchar(max)       | uniqueidentifier                     | uniqueidentifier                     |
|--------------------|--------------------------------------|--------------------------------------|
| 'Hello'            | C6705EDE-CE58-4AB9-81BE-679AC1E75DE6 | 2466C151-88EC-40C0-B091-25B6BD74070C |

注意：显然，当我发现错误时，我正在从真实的表中选择真实数据。在我创建MRCE的过程中，发现上述与数据库无关的查询也会触发失败。

我正在使用ADO（本机COM）和 SQL Server ODBC驱动程序连接到SQL Server：

Provider=MSDASQL;Driver={SQL Server};Server={vader};Database=master;Trusted_Connection=Yes;

读取列C首先导致ColumnB为空

在此MRCE中，我只读取两个uniqueidentifier列的值。

recordset.Fields['ColumnB'].Value;
recordset.Fields['ColumnC'].Value;

如果我按顺序读取两列，则值正确无误：

ColumnB ："C6705EDE-CE58-4AB9-81BE-679AC1E75DE6"（变体类型VT_BSTR）
ColumnC ："2466C151-88EC-40C0-B091-25B6BD74070C"（变体类型VT_BSTR）

但是，如果我按其他顺序读取列值：

ColumnC ："2466C151-88EC-40C0-B091-25B6BD74070C"（变体类型VT_BSTR）
ColumnB ： (empty) （变体类型VT_EMPTY）

最小代码示例（C＃）

using System;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            TestIt();
        }

        private static void TestIt()
        {
            String serverName = "vader";
            String CRLF = "\r\n";

            String connectionString = "Provider=MSDASQL;Driver={SQL Server};Server={" + serverName + "};Database=master;Trusted_Connection=Yes;";
            WriteLn("ConnectionString: " + connectionString);
            WriteLn("");

            Int32 adOpenForwardOnly = 0;
            Int32 adLockReadOnly = 1;
            Int32 adCmdText = 1;

            dynamic rs = CreateOleObject("ADODB.Recordset");

            String sql = "SELECT " + CRLF +
                " CAST('Hello' AS varchar(max)) AS ColumnA, " + CRLF +
                " CAST('C6705EDE-CE58-4AB9-81BE-679AC1E75DE6' AS uniqueidentifier) AS ColumnB," + CRLF +
                " CAST('2466C151-88EC-40C0-B091-25B6BD74070C' AS uniqueidentifier) AS ColumnC";

            WriteLn("Command text:");
            WriteLn(sql);
            WriteLn("");

            WriteLn("Executing query");
            rs.open(sql, connectionString, adOpenForwardOnly, adLockReadOnly, adCmdText);
            WriteLn("Query complete");

            if (rs.EOF) return; //just to shut people up

            var columnC = rs("ColumnC").Value;
            var columnB = rs("ColumnB").Value;

            WriteLn("ColumnB: " + columnB);
            WriteLn("ColumnC: " + columnC);
        }

        private static dynamic CreateOleObject(string progID)
        {
            Type comType = Type.GetTypeFromProgID(progID);
            var instance = Activator.CreateInstance(comType);

            return instance;
        }

        private static void WriteLn(string v)
        {
            Console.WriteLine(v);
        }
    }
}

结果：

ConnectionString: Provider=MSDASQL;Driver={SQL Server};Server={vader};Database=master;Trusted_Connection=Yes;

Command text:
SELECT
 CAST('Hello' AS varchar(max)) AS ColumnA,
 CAST('C6705EDE-CE58-4AB9-81BE-679AC1E75DE6' AS uniqueidentifier) AS ColumnB,
 CAST('2466C151-88EC-40C0-B091-25B6BD74070C' AS uniqueidentifier) AS ColumnC

Executing query
Query complete
ColumnB:
ColumnC: {2466C151-88EC-40C0-B091-25B6BD74070C}

最小代码示例（Delphi）

program Project3;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  System.SysUtils,
  ADOInt,
  ComObj,
    ActiveX;

function DataTypeEnumToStr(t: DataTypeEnum): string;
begin
    case t of
    adEmpty: Result := 'adEmpty';
    adSmallInt: Result := 'adSmallInt';
    adInteger: Result := 'adInteger';
    adTinyInt: Result := 'adTinyInt';
    adBigInt: Result := 'adBigInt';
    adUnsignedTinyInt: Result := 'adUnsignedTinyInt';
    adUnsignedSmallInt: Result := 'adUnsignedSmallInt';
    adUnsignedInt: Result := 'adUnsignedInt';
    adUnsignedBigInt: Result := 'adUnsignedBigInt';
    adSingle: Result := 'adSingle';
    adDouble: Result := 'adDouble';
    adCurrency: Result := 'adCurrency';
    adDecimal: Result := 'adDecimal';
    adNumeric: Result := 'adNumeric';
    adBoolean: Result := 'adBoolean';
    adError: Result := 'adError';
    adUserDefined: Result := 'adUserDefined';
    adVariant: Result := 'adVariant';
    adIDispatch: Result := 'adIDispatch';
    adIUnknown: Result := 'adIUnknown';
    adGUID: Result := 'adGUID';
    adDate: Result := 'adDate';
    adDBDate: Result := 'adDBDate';
    adDBTime: Result := 'adDBTime';
    adDBTimeStamp: Result := 'adDBTimeStamp';
    adBSTR: Result := 'adBSTR';
    adChar: Result := 'adChar';
    adVarChar: Result := 'adVarChar';
    adLongVarChar: Result := 'adLongVarChar';
    adWChar: Result := 'adWChar';
    adVarWChar: Result := 'adVarWChar';
    adLongVarWChar: Result := 'adLongVarWChar';
    adBinary: Result := 'adBinary';
    adVarBinary: Result := 'adVarBinary';
    adLongVarBinary: Result := 'adLongVarBinary';
    adChapter: Result := 'adChapter';
    adFileTime: Result := 'adFileTime';
    adDBFileTime: Result := 'adDBFileTime';
    adPropVariant: Result := 'adPropVariant';
    adVarNumeric: Result := 'adVarNumeric';
    adArray: Result := 'adArray';
    else
        Result := IntToStr(t);
    end;
end;

procedure TestLoadingGUID;
var
    connectionString: string;
    sql: string;
    rs: _Recordset;
    s: string;
    guid: TGUID;
    i: Integer;
    fld: Field;

    function DumpField(const FieldName: string): string;
    var
        sValue: string;
        vt: TVarType;
        value: OleVariant;
    begin
        WriteLn('Reading '+FieldName+' column');
        value := rs.Fields[FieldName].Value;

        sValue := value;
        vt := TVarData(value).VType;
        WriteLn('   VType: '+IntToStr(vt));
        WriteLn('   Value: "'+sValue+'" (as string)');
        WriteLn('');
    end;

begin
{
    Tested:
        Windows 10
        Windows 7

        Microsoft SQL Server 2012 (SP3)
        Microsoft SQL Server 2008 R2 (SP2)
        Microsoft SQL Server 2005 - 9.00.5000.00 (Intel X86)
}

    Write('Enter name of server to connect to (leave blank for VADER): ');
    ReadLn(s);

    if s = '' then
        s := 'vader';

    connectionString := 'Provider=MSDASQL;Driver={SQL Server};Server={'+s+'};Database=master;Trusted_Connection=Yes;';
    WriteLn('ConnectionString: '+connectionString);
    WriteLn;


//  sql := 'SELECT CAST(NULL AS varchar(max)) AS ColumnA, newid() AS ColumnB, newid() as ColumnC';
    sql := 'SELECT '+#13#10+
            '   CAST(''Hello'' AS varchar(max)) AS ColumnA, '+#13#10+
            '   CAST(''C6705EDE-CE58-4AB9-81BE-679AC1E75DE6'' AS uniqueidentifier) AS ColumnB,'+#13#10+
            '   CAST(''2466C151-88EC-40C0-B091-25B6BD74070C'' AS uniqueidentifier) AS ColumnC';


    rs := CoRecordset.Create;
    rs.Open(sql, connectionString, adOpenForwardOnly, adLockReadOnly, adCmdText);
    WriteLn('');

    WriteLn('Command text: ');
    WriteLn(sql);
    WriteLn;

    if rs.EOF then Exit; //just to shut people up

    WriteLn('Recordset Fields');
    for i := 0 to rs.Fields.Count-1 do
    begin
        fld := rs.Fields[i];
        if fld.DefinedSize = MaxInt then
            WriteLn(Format('   %d.  %s: %s(%s)', [i, fld.Name, DataTypeEnumToStr(fld.Type_), 'max']))
        else
            WriteLn(Format('   %d.  %s: %s(%d)', [i, fld.Name, DataTypeEnumToStr(fld.Type_), fld.DefinedSize]));
    end;
    WriteLn('');
    WriteLn('');

    WriteLn('Fields["ColumnA"]: "'+rs.Fields['ColumnA'].Value+'"  (VType: '+IntToStr(TVarData(rs.Fields['ColumnA'].Value).VType)+')');
    WriteLn('Fields["ColumnC"]: "'+rs.Fields['ColumnC'].Value+'"  (VType: '+IntToStr(TVarData(rs.Fields['ColumnC'].Value).VType)+')');
    WriteLn('Fields["ColumnB"]: "'+rs.Fields['ColumnB'].Value+'"  (VType: '+IntToStr(TVarData(rs.Fields['ColumnB'].Value).VType)+')');
    WriteLn('');

    WriteLn('Fields[0]: "'+rs.Fields[0].Value+'"  (VType: '+IntToStr(TVarData(rs.Fields[0].Value).VType)+')');
    WriteLn('Fields[2]: "'+rs.Fields[2].Value+'"  (VType: '+IntToStr(TVarData(rs.Fields[2].Value).VType)+')');
    WriteLn('Fields[1]: "'+rs.Fields[1].Value+'"  (VType: '+IntToStr(TVarData(rs.Fields[1].Value).VType)+')');
    WriteLn('');



    DumpField('ColumnA');
    DumpField('ColumnB');
    s := DumpField('ColumnC');

    if s = '' then
    begin
        WriteLn(Format('WARNING: ColumnB expected to not-empty, but was "%s"',  [s]));
        Exit;
    end;
end;


begin
  try
        CoInitialize(nil);
        TestLoadingGUID;
  except
     on E: Exception do
        Writeln(E.ClassName, ': ', E.Message);
  end;

    WriteLn('Press enter to close');
    Readln;
end.

控制台输出

Enter name of server to connect to (leave blank for VADER):
ConnectionString: Provider=MSDASQL;Driver={SQL Server};Server={vader};Database=master;Trusted_Connection=Yes;


Command text:
SELECT
        CAST('Hello' AS varchar(max)) AS ColumnA,
        CAST('C6705EDE-CE58-4AB9-81BE-679AC1E75DE6' AS uniqueidentifier) AS ColumnB,
        CAST('2466C151-88EC-40C0-B091-25B6BD74070C' AS uniqueidentifier) AS ColumnC

Recordset Fields
   0.  ColumnA: adLongVarChar(max)
   1.  ColumnB: adGUID(16)
   2.  ColumnC: adGUID(16)


Fields["ColumnA"]: "Hello"  (VType: 1)
Fields["ColumnC"]: "{2466C151-88EC-40C0-B091-25B6BD74070C}"  (VType: 8)
Fields["ColumnB"]: ""  (VType: 0)

Fields[0]: ""  (VType: 0)
Fields[2]: "{2466C151-88EC-40C0-B091-25B6BD74070C}"  (VType: 8)
Fields[1]: ""  (VType: 0)

Reading ColumnA column
   VType: 0
   Value: "" (as string)

Reading ColumnB column
   VType: 0
   Value: "" (as string)

Reading ColumnC column
   VType: 8
   Value: "{2466C151-88EC-40C0-B091-25B6BD74070C}" (as string)

WARNING: ColumnB expected to not-empty, but was ""
Press enter to close

最小代码示例（Javascript）

为了扩大受众群体，以下是javascript中的相同代码：

OdbcFails.js

main();

function main() {
  serverName = "vader";
  CRLF = "\r\n";

  var connectionString = "Provider=MSDASQL;Driver={SQL Server};Server={"+serverName+"};Database=master;Trusted_Connection=Yes;";
    WriteLn("ConnectionString: "+connectionString);
    WriteLn("");

  adOpenForwardOnly = 0;
  adLockReadOnly = 1;
  adCmdText = 1;
  var rs = new ActiveXObject("ADODB.Recordset");

  var sql = "SELECT "+CRLF+
            " CAST('Hello' AS varchar(max)) AS ColumnA, "+CRLF+
            " CAST('C6705EDE-CE58-4AB9-81BE-679AC1E75DE6' AS uniqueidentifier) AS ColumnB,"+CRLF+
            " CAST('2466C151-88EC-40C0-B091-25B6BD74070C' AS uniqueidentifier) AS ColumnC";

    WriteLn("Command text:");
    WriteLn(sql);
    WriteLn("");

  WriteLn("Executing query");
  rs.open(sql, connectionString, adOpenForwardOnly, adLockReadOnly, adCmdText);
  WriteLn("Query complete");

    if (rs.EOF) return; //just to shut people up

  var columnC = rs("ColumnC").Value;
  var columnB = rs("ColumnB").Value;

   WriteLn("ColumnB: "+columnB);
   WriteLn("ColumnC: "+columnC);

}

function WriteLn(str) {
  WScript.Echo(str);
}

如果你跑：

C:\Users\ian>cscript OdbcFails.js

Microsoft (R) Windows Script Host Version 5.812
Copyright (C) Microsoft Corporation. All rights reserved.

ConnectionString: Provider=MSDASQL;Driver={SQL Server};Server={vader};Database=master;Trusted_Connection=Yes;

Command text:
SELECT
 CAST('Hello' AS varchar(max)) AS ColumnA,
 CAST('C6705EDE-CE58-4AB9-81BE-679AC1E75DE6' AS uniqueidentifier) AS ColumnB,
 CAST('2466C151-88EC-40C0-B091-25B6BD74070C' AS uniqueidentifier) AS ColumnC

Executing query
Query complete
ColumnB: undefined
ColumnC: {2466C151-88EC-40C0-B091-25B6BD74070C}

最小代码示例（html + javascript - 仅限Internet Explorer）

<!doctype html>
<html>

<head>
    <script>
        function WriteLn(str) {
            console.log(str);
        }

        function main() {
            serverName = "vader";
            CRLF = "\r\n";

            var connectionString = "Provider=MSDASQL;Driver={SQL Server};Server={" + serverName + "};Database=master;Trusted_Connection=Yes;";
            WriteLn("ConnectionString: " + connectionString);
            WriteLn("");

            adOpenForwardOnly = 0;
            adLockReadOnly = 1;
            adCmdText = 1;
            var rs = new ActiveXObject("ADODB.Recordset");

            var sql = "SELECT " + CRLF +
                " CAST('Hello' AS varchar(max)) AS ColumnA, " + CRLF +
                " CAST('C6705EDE-CE58-4AB9-81BE-679AC1E75DE6' AS uniqueidentifier) AS ColumnB," + CRLF +
                " CAST('2466C151-88EC-40C0-B091-25B6BD74070C' AS uniqueidentifier) AS ColumnC";

            WriteLn("Command text:");
            WriteLn(sql);
            WriteLn("");

            WriteLn("Executing query");
            rs.open(sql, connectionString, adOpenForwardOnly, adLockReadOnly, adCmdText);
            WriteLn("Query complete");

            if (rs.EOF) return; //just to shut people up

            var columnC = rs("ColumnC").Value;
            var columnB = rs("ColumnB").Value;

            WriteLn("ColumnB: " + columnB);
            WriteLn("ColumnC: " + columnC);

        }

        main();

    </script>

    <body>
    </body>
    <script>

奖金阅读

MSDN博客：Microsoft is Aligning with ODBC for Native Relational Data Access （archive）
ADO.Net博客：Microsoft SQL Server OLEDB Provider Deprecation Announcement （archive）
MSDN：Converting SQL Server Applications from OLE DB to ODBC （archive）
HAL2020：OLE DB and SQL Server: History, End-Game, and some Microsoft “dirt” （archive）
- Invalid descriptor index reading varchar(max) （archive）
MSDN论坛：Invalid Descriptor Index calling SQLGetData （archive）
IBM：DataStage job with ODBC Connector receives an error when using LOB Column （archive）

Answer 1

答案是这个行为不会在ODBC驱动程序中修复。

在20世纪80年代后期，强制客户端只按行顺序读取行缓冲区中的列，这有一个性能优势。您可以询问驱动程序是否允许您通过SqlGetInfo function：

以任何顺序读取列值

SqlGetInfo(..., SQL_GD_ANY_ORDER, ...) //returns true or false

SQL_GD_ANY_COLUMN = SQLGetData ，包括最后一个绑定列之前的列。请注意，必须按列号递增的顺序调用列，除非还返回SQL_GD_ANY_ORDER。
SQL_GD_ANY_ORDER = SQLGetData 。请注意，除非还返回SQL_GD_ANY_COLUMN，否则只能为最后一个绑定列之后的列调用 SQLGetData 。

即使计算机目前有超过4MB的RAM，Windows 3.0时代的现代SQL Server ODBC驱动程序continues to opt-in to this limitation：

SQL Server Native Client ODBC驱动程序不支持使用SQLGetData以随机列顺序检索数据。

他们非常可以支持这样的事情，如17岁的OLEDB驱动程序，以及ADO.NET SqlClient驱动程序。但他们没有;所以ODBC驱动程序是脑死亡的憎恶，不适合现实世界的使用。

您需要继续使用：

SQLOLEDB（supported）
SQLNCLI（已弃用）
ADO.net SqlClient（支持）

奖金阅读

ODBC Driver 11 for SQL Server and SQLGetData limitations
Client Driver Support Policies
- OLE DB支持策略：应用程序应使用Windows操作系统附带的SQL Server OLE DB提供程序。
- ADO支持策略：如果不需要SQL Server 2005或更高版本的任何功能，ADO应用程序可以使用Windows附带的SQLOLEDB OLE DB提供程序。

无序读取列返回不正确的值（SQL Server ODBC驱动程序）

短版

背景

读取列C首先导致ColumnB为空

最小代码示例（C＃）

最小代码示例（Delphi）

最小代码示例（Javascript）

最小代码示例（html + javascript - 仅限Internet Explorer）

奖金阅读

1 个答案: