我如何仅捕获FireDac连接上的mysql_real_query？
我在Delphi上具有带有TFDMonicustomClientLink的FireDac连接。我需要仅捕获mysql_real_query。我尝试启用和禁用所有事件界，但我找不到方法。我发现的距离越近是仅启用Ekvendor，但是它的信息比mysql_real_query。
。编辑：MySQL_REAL_QUERY是TFDMonicustomClientElink生成的日志文本文件的一节。本节显示在数据库上执行的SQL。我在此术语中发现的唯一参考文献是：http：//docwiki.embarcadero.com/libraries/libraries/berlin/en/firedac.phys.mysqlwrapper.tmysqllapper.tmysqllib.mysql.mysql_real_query和此处refman/5.7/en/mysql-real-query.html。
tfdmonicustomclientlink的OnOutput事件中的代码：
procedure TDmConnX.FDMonitorOutput(ASender: TFDMoniClientLinkBase;
const AClassName, AObjName, AMessage: string);
var
lstLog: TStringList;
sFile: ShortString;
begin
lstLog := TStringList.Create;
try
sFile := 'C:log.txt';
if FileExists(sFile) then
lstLog.LoadFromFile(sFile);
lstLog.Add(AMessage);
lstLog.SaveToFile(sFile);
finally
lstLog.Free;
end;
end;
生成的日志文件：
. mysql_get_client_info [Ver="5.1.37"]
. mysql_init
. mysql_options [option=1, arg=0]
. mysql_real_connect [host="127.0.0.1", user="user", passwd="***", db="banco", port=3306, clientflag=198158]
. mysql_get_server_info [Ver="5.1.73-community"]
. mysql_real_query [q="SET SQL_AUTO_IS_NULL = 0
. mysql_insert_id [res=0]
. mysql_real_query [q="SHOW VARIABLES LIKE 'lower_case_table_names'
. mysql_store_result
. mysql_fetch_row [res=$06530BE8]
. mysql_fetch_lengths [res=$06530BE8]
. mysql_free_result [res=$06530BE8]
. mysql_get_server_info [Ver="5.1.73-community"]
. mysql_get_client_info [Ver="5.1.37"]
. mysql_character_set_name [res="latin1"]
. mysql_get_host_info [res="127.0.0.1 via TCP/IP"]
. mysql_get_server_info [Ver="5.1.73-community"]
. mysql_get_client_info [Ver="5.1.37"]
. mysql_character_set_name [res="latin1"]
我只需要捕获SQL，消除事件" 。mysql_real_query [q =" "
我希望有一些配置可以更改以导出实际SQL，而没有各个部分，因此我无需检查字符串中的模式。
在发货的跟踪监视器上不可能做什么。这是因为FireDac的跟踪不是为自定义条目开发的，并且正如您正确识别的那样， mysql_real_query API函数的调用是由 ekvendor 进行分类的，因此没有办法区分任何方法在此类消息之间，除了解析消息本身之外，这是丑陋的方式。因此，让我们尝试以不同的方式去。
1。读取传递给DBMS
的SQL命令从问题中不清楚，但是您在评论中确认您实际上只想记录传递给DBMS的SQL命令。如果您丢失了使用跟踪监视器的可能性，则可以从 text 属性中读取SQL命令(实际上是在中涵盖的检查SQL命令text >章(。
如果 efdddbengineException 升高了例外，则可以从其 sql 属性中读取SQL命令(在提到的一章中也涵盖(。
(。2。拦截特定的DBMS API函数
如果您想遵守监视特定API函数调用而不更改FireDac源的想法，则可以为驾驶员的 on driverCreated 事件编写处理程序，请拦截您感兴趣的函数，存储原始的函数指针和执行所需的操作(包括调用原始存储的功能(截距功能主体。例如，对于 mysql_real_query 函数，可能是这样的：
uses
FireDAC.Phys.MySQLWrapper, FireDAC.Phys.MySQLCli;
var
OrigRealQuery: TPrcmysql_real_query;
function MyRealQueryIntercept(mysql: PMYSQL; const q: my_pchar; length: my_ulong): Integer;
{$IFDEF MSWINDOWS} stdcall {$ELSE} cdecl {$ENDIF};
begin
{ ← do whatever you need before the original function call }
Result := OrigRealQuery(mysql, q, length); { ← call the original function }
{ ← do whatever you need after the original function call }
end;
procedure TForm1.FDPhysMySQLDriverLink1DriverCreated(Sender: TObject);
var
CliLib: TMySQLLib;
begin
CliLib := TMySQLLib(TFDPhysMySQLDriverLink(Sender).DriverIntf.CliObj);
OrigRealQuery := CliLib.mysql_real_query; { ← store the original function }
CliLib.mysql_real_query := MyRealQueryIntercept; { ← replace current with intercept }
end;
但是，这种方式非常具体，花费您额外的功能呼叫开销。
3。写自己的跟踪监视器
跟踪监视器并不像以前那样灵活，但是仍然有办法编写自己的信息并接收到传递给 notify 方法而不是串联消息的信息(但是，您当然必须，您必须知道跟踪通知参数的含义(。
这是我由 tfdmonicustomclientlink class制作的一个示例(但这对已使用的RTTI不利，但是您可以自己调整它(：
>unit FireDAC.Moni.Extended;
interface
uses
System.SysUtils, System.Classes, System.Rtti, FireDAC.Stan.Intf, FireDAC.Moni.Base;
type
IFDMoniClientNotifyHandler = interface(IFDMoniClientOutputHandler)
['{32F21585-F9CC-4C41-A7DF-10B8C1B98006}']
procedure HandleNotify(AKind: TFDMoniEventKind; AStep: TFDMoniEventStep;
ASender: TObject; const AMsg: string; const AArgs: TArray<TValue>);
end;
TFDMoniExtendedClient = class(TFDMoniClientBase, IFDMoniCustomClient)
private
FSynchronize: Boolean;
function GetSynchronize: Boolean;
procedure SetSynchronize(AValue: Boolean);
protected
procedure Notify(AKind: TFDMoniEventKind; AStep: TFDMoniEventStep;
ASender: TObject; const AMsg: string; const AArgs: array of const); override;
public
destructor Destroy; override;
end;
TFDMoniNotifyEvent = procedure(ASender: TObject; AKind: TFDMoniEventKind;
AStep: TFDMoniEventStep; const AMsg: string; const AArgs: TArray<TValue>) of object;
TFDMoniExtendedClientLink = class(TFDMoniClientLinkBase, IFDMoniClientNotifyHandler)
private
FOnNotify: TFDMoniNotifyEvent;
FExClient: IFDMoniCustomClient;
function GetSynchronize: Boolean;
procedure SetSynchronize(AValue: Boolean);
procedure SetOnNotify(AValue: TFDMoniNotifyEvent);
protected
function GetMoniClient: IFDMoniClient; override;
procedure HandleNotify(AKind: TFDMoniEventKind; AStep: TFDMoniEventStep;
ASender: TObject; const AMsg: string; const AArgs: TArray<TValue>); virtual;
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
property ExClient: IFDMoniCustomClient read FExClient;
published
property Tracing;
property Synchronize: Boolean read GetSynchronize write SetSynchronize default False;
property OnNotify: TFDMoniNotifyEvent read FOnNotify write SetOnNotify;
end;
implementation
uses
FireDAC.Stan.Factory;
type
TFDMoniExtendedClientMsg = class
private
FMsg: string;
FArgs: TArray<TValue>;
FKind: TFDMoniEventKind;
FStep: TFDMoniEventStep;
FSender: TObject;
FClient: IFDMoniCustomClient;
protected
procedure DoNotify; virtual;
public
constructor Create(const AClient: IFDMoniCustomClient; ASender: TObject;
AKind: TFDMoniEventKind; AStep: TFDMoniEventStep; const AMsg: string;
const AArgs: TArray<TValue>);
end;
{ TFDMoniExtendedClientMsg }
constructor TFDMoniExtendedClientMsg.Create(const AClient: IFDMoniCustomClient;
ASender: TObject; AKind: TFDMoniEventKind; AStep: TFDMoniEventStep;
const AMsg: string; const AArgs: TArray<TValue>);
var
I: Integer;
begin
inherited Create;
FMsg := AMsg;
SetLength(FArgs, Length(AArgs));
for I := Low(FArgs) to High(FArgs) do
FArgs[I] := AArgs[I];
FKind := AKind;
FStep := AStep;
FSender := ASender;
FClient := AClient;
end;
procedure TFDMoniExtendedClientMsg.DoNotify;
var
Handler: IFDMoniClientNotifyHandler;
begin
if Supports(FClient.OutputHandler, IFDMoniClientNotifyHandler, Handler) then
Handler.HandleNotify(FKind, FStep, FSender, FMsg, FArgs);
Destroy;
end;
{ TFDMoniExtendedClient }
destructor TFDMoniExtendedClient.Destroy;
begin
SetTracing(False);
inherited;
end;
function TFDMoniExtendedClient.GetSynchronize: Boolean;
begin
Result := FSynchronize;
end;
procedure TFDMoniExtendedClient.SetSynchronize(AValue: Boolean);
begin
FSynchronize := AValue;
end;
procedure TFDMoniExtendedClient.Notify(AKind: TFDMoniEventKind; AStep: TFDMoniEventStep;
ASender: TObject; const AMsg: string; const AArgs: array of const);
var
InArray: TArray<TValue>;
Payload: TFDMoniExtendedClientMsg;
Handler: IFDMoniClientNotifyHandler;
begin
if Supports(GetOutputHandler, IFDMoniClientNotifyHandler, Handler) then
begin
InArray := ArrayOfConstToTValueArray(AArgs);
if TThread.CurrentThread.ThreadID = MainThreadID then
Handler.HandleNotify(AKind, AStep, ASender, AMsg, InArray)
else
begin
Payload := TFDMoniExtendedClientMsg.Create(Self, ASender, AKind, AStep, AMsg, InArray);
TThread.Queue(nil, Payload.DoNotify);
end;
end;
inherited;
end;
{ TFDMoniExtendedClientLink }
constructor TFDMoniExtendedClientLink.Create(AOwner: TComponent);
begin
inherited;
FExClient := MoniClient as IFDMoniCustomClient;
end;
destructor TFDMoniExtendedClientLink.Destroy;
begin
FExClient := nil;
inherited;
end;
function TFDMoniExtendedClientLink.GetSynchronize: Boolean;
begin
Result := FExClient.Synchronize;
end;
procedure TFDMoniExtendedClientLink.SetSynchronize(AValue: Boolean);
begin
FExClient.Synchronize := AValue;
end;
procedure TFDMoniExtendedClientLink.SetOnNotify(AValue: TFDMoniNotifyEvent);
begin
if (TMethod(FOnNotify).Code <> TMethod(AValue).Code) or
(TMethod(FOnNotify).Data <> TMethod(AValue).Data) then
begin
if Assigned(AValue) then
MoniClient.OutputHandler := Self as IFDMoniClientNotifyHandler
else
MoniClient.OutputHandler := nil;
FOnNotify := AValue;
end;
end;
function TFDMoniExtendedClientLink.GetMoniClient: IFDMoniClient;
var
Client: IFDMoniCustomClient;
begin
FDCreateInterface(IFDMoniCustomClient, Client);
Result := Client as IFDMoniClient;
end;
procedure TFDMoniExtendedClientLink.HandleNotify(AKind: TFDMoniEventKind;
AStep: TFDMoniEventStep; ASender: TObject; const AMsg: string; const AArgs: TArray<TValue>);
begin
if Assigned(FOnNotify) and not (csDestroying in ComponentState) then
FOnNotify(Self, AKind, AStep, AMsg, AArgs);
end;
var
Factory: TFDFactory;
initialization
Factory := TFDSingletonFactory.Create(TFDMoniExtendedClient, IFDMoniCustomClient);
finalization
FDReleaseFactory(Factory);
end.
重要，当使用这样的类时，您必须 not include firedAc.moni.custom 模块在您的项目中，否则 ifdmonicustomclient接口将在其他类中注册(这是因为 mbCustom的跟踪监视> ifdmonicustomclient 接口;这是在上述单元的初始化块中所做的。
简化的使用示例：
uses
System.Rtti, FireDAC.Moni.Extended;
type
TForm1 = class(TForm)
FDPhysMySQLDriverLink1: TFDPhysMySQLDriverLink;
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure FDPhysMySQLDriverLink1DriverCreated(Sender: TObject);
private
FMonitor: TFDMoniExtendedClientLink;
procedure MonitorNotify(ASender: TObject; AKind: TFDMoniEventKind;
AStep: TFDMoniEventStep; const AMsg: string; const AArgs: TArray<TValue>);
end;
implementation
procedure TForm1.FormCreate(Sender: TObject);
begin
FMonitor := TFDMoniExtendedClientLink.Create(nil);
FMonitor.OnNotify := MonitorNotify;
FMonitor.EventKinds := [ekVendor];
FMonitor.Tracing := True;
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
FMonitor.Free;
end;
procedure TForm1.MonitorNotify(ASender: TObject; AKind: TFDMoniEventKind;
AStep: TFDMoniEventStep; const AMsg: string; const AArgs: TArray<TValue>);
begin
if (AKind = ekVendor) and (AStep = esProgress) and (AMsg = 'mysql_real_query') and
(Length(AArgs) >= 1) and (AArgs[1].IsType<string>)
then
ShowMessage(AArgs[1].AsType<string>);
end;
这种方式对您的需求也非常具体，并且花费了新RTTI的额外开销，但这就是您可以优化的。