我创建了一个vcl组件，该组件使用firedac访问PostgreSQL数据库。除查询跟踪之外，其他方法都无法正常工作。
在组件构造函数中，我创建连接对象，设置参数等。在uses子句中，我添加了FireDAC.Phys.PG和FireDAC.Moni.Base，FireDAC.Moni.FlatFile。
在embarcadero文档之后，在TFDConnection之前创建了TFDMoniFlatFileClientLink，并将跟踪设置为true 对于FDTracer和FDConnection.ConnectionIntf。
unit My.Database;
interface
uses
System.SysUtils, System.Classes, FireDAC.Comp.UI, FireDAC.Comp.Client, FireDAC.Phys.PG,
FireDAC.Moni.Base, FireDAC.Moni.FlatFile;
type
TMyDatabase = class(TComponent)
private
{ Private declarations }
FDTracer: TFDMoniFlatFileClientLink;
FDConnection: TFDConnection;
FConnectionString: string;
public
{ Public declarations }
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
function IsConnected: Boolean;
property ConnectionString: stringread FConnectionString write FConnectionString;
function OpenConnection: Boolean;
function GetAsDataset(ASQL: string): TFDQuery;
end;
implementation
uses
FireDAC.Stan.Intf, FireDAC.Stan.Option, FireDAC.Stan.Error, FireDAC.Stan.Def, FireDAC.Stan.Async,
FireDAC.VCLUI.Login, FireDAC.VCLUI.Wait;
constructor TMyDatabase.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FDTracer := TFDMoniFlatFileClientLink.Create(Self);
FDConnection := TFDConnection.Create(Self);
FDTracer.tracing := True;
with FDConnection do
begin
DriverName := 'PG';
LoginPrompt := False;
//params for PostgreSQL
with Params do
begin
Add('Port=5432');
Add('LoginTimeout=2');
Add('Pooled=False');
Add('OidAsBlob=No');
Add('UnknownFormat=BYTEA');
Add('ExtendedMetadata=True');
end;
end;
FDConnection.ConnectionIntf.Tracing := True;
end;
function TMyDatabase.IsConnected: Boolean;
begin
Result := FDConnection.Connected;
end;
function TMyDatabase.OpenConnection: Boolean;
begin
with FDConnection do
try
ConnectionString := FConnectionString;
if not Connected then
begin
Open;
end;
finally
Result := Connected;
end;
end;
function TMyDatabase.GetAsDataset(ASQL: string): TFDQuery;
begin
Result := TFDQuery.Create(Self);
with Result do
begin
Connection := FDConnection;
end;
Result.Open(ASQL);
end;
当我连接到数据库并通过GetAsDataSet执行查询时，跟踪文件仅记录FireDac连接的开始/停止，而不记录 查询的执行。如果我将TFDConnection和TFDMoniFlatFileClientLink组件放在表单或数据模块上，则会按预期跟踪查询执行。
谁知道如何使用从组件动态创建的连接对象来跟踪查询的执行？
最诚挚的问候，罗纳德
答案 0 :(得分：2)
我试图通过添加一个简单的FireDAC测试平台来重现您的问题
TFDMoniFlatFileClientLink并得到类似结果，即跟踪文件
包含条目说它已经启动和停止，但是中间没有。
看着http://docwiki.embarcadero.com/CodeExamples/Tokyo/en/FireDAC.MoniLayerClients_Sample
我似乎错过了一个小而重要的步骤，即设置MonitorBy参数
我的FDConnection到'FlatFile'，以匹配TFDMoniFlatFileClientLink
因此，在我的代码中打开连接之前，我在下面添加了第一行
FDConnection1.Params.MonitorBy := mbFlatFile;
FDConnection1.Connected := True;
然后跟踪运行正常。
部分痕迹提取物
--- new start of FireDAC Trace ---
4361928750001 19:48:07.092 -=#!!! FireDAC Tracer started !!!#=-
4361928750001 19:48:07.094 TFDPhysMSSQLConnection TFDPhysMSSQLConnecti . CreateConnection [ConnectionDef=""]
4361928750001 19:48:07.094 TFDPhysMSSQLConnection TFDPhysMSSQLConnecti . CreateTransaction [ConnectionDef=""]
4361928750001 19:48:07.094 TFDPhysMSSQLConnection FDConnection1 >> Open [ConnectionDef=""]
4361928750001 19:48:07.094 TFDConnectionDef $0100C390 >> Definition [Name=""]
4361928750001 19:48:07.094 TFDConnectionDef $0100C390 . Server=MAT430\ss2014
4361928750001 19:48:07.094 TFDConnectionDef $0100C390 . User_Name=sa
4361928750001 19:48:07.094 TFDConnectionDef $0100C390 . Password=*****
4361928750001 19:48:07.094 TFDConnectionDef $0100C390 . Database=MAtest
4361928750001 19:48:07.094 TFDConnectionDef $0100C390 . OSAuthent=No
4361928750001 19:48:07.094 TFDConnectionDef $0100C390 . DriverID=MSSQL
4361928750001 19:48:07.094 TFDConnectionDef $0100C390 . MonitorBy=FlatFile
4361928750001 19:48:07.094 TFDConnectionDef $0100C390 << Definition [Name=""]
4361928750001 19:48:07.094 TFDPhysMSSQLConnection FDConnection1 >> FireDAC info
4361928750001 19:48:07.094 TFDPhysMSSQLConnection FDConnection1 . Tool=RAD Studio 10.2
4361928750001 19:48:07.094 TFDPhysMSSQLConnection FDConnection1 . FireDAC=16.0.0 (Build 88974)
4361928750001 19:48:07.094 TFDPhysMSSQLConnection FDConnection1 . Platform=Windows 32 bit
4361928750001 19:48:07.094 TFDPhysMSSQLConnection FDConnection1 . Defines=FireDAC_NOLOCALE_META;FireDAC_MONITOR
4361928750001 19:48:07.094 TFDPhysMSSQLConnection FDConnection1 << FireDAC info
4361931710001 19:48:07.390 TFDPhysMSSQLConnection FDConnection1 . SQLDriverConnect [szConnStr="DRIVER=SQL Server Native Client 11.0;UID=sa;PWD=*******;Server=MAT430\ss2014;Database=MAtest;Trusted_Connection=No;MARS_Connection=yes"]
4361931710001 19:48:07.392 TFDPhysMSSQLDriver MSSQL . ENTER SQLDriverConnectW
HDBC 0x01044B18
HWND 0x00000000
WCHAR * 0x61942440 [ -3] "******\ 0"
SWORD -3
WCHAR * 0x61942440
SWORD -3
SWORD * 0x00000000
UWORD 0 <SQL_DRIVER_NOPROMPT>
4361935310001 19:48:07.756 TFDPhysMSSQLDriver MSSQL . EXIT SQLDriverConnectW with return code 1 (SQL_SUCCESS_WITH_INFO)
HDBC 0x01044B18
HWND 0x00000000
WCHAR * 0x61942440 [ -3] "******\ 0"
SWORD -3
WCHAR * 0x61942440 <Invalid buffer length!> [-3]
SWORD -3
SWORD * 0x00000000
UWORD 0 <SQL_DRIVER_NOPROMPT>
DIAG [01000] [Microsoft][SQL Server Native Client 11.0][SQL Server]Changed database context to 'MAtest'. (5701)
DIAG [01000] [Microsoft][SQL Server Native Client 11.0][SQL Server]Changed language setting to us_english. (5703)
4361935310001 19:48:07.758 TFDPhysMSSQLDriver MSSQL . ENTER SQLGetDiagRecW
SQLSMALLINT 2 <SQL_HANDLE_DBC>
SQLHANDLE 0x01044B18
SQLSMALLINT 1
SQLWCHAR * 0x00FCB5CC
SQLINTEGER * 0x0019F840
SQLWCHAR * 0x0019D83A
SQLSMALLINT 4096
SQLSMALLINT * 0x0019F846
然后是厨房水槽的其余部分。