delphi FireDac -为什么数据库路径限制为128？

hjzp0vay 于 2023-06-22 发布在其他

关注(0)|答案(1)|浏览(111)

我想在数据库路径大于128时执行查询。这是一些客户的需要。
不起作用的例子。数据库路径大于128。我得到以下错误消息：
[FireDac][DatS]-32。列溢出[CATALOG_NAME]变量长度。值长度-[219]，最大列长度-[128]。

try
    Connection := TFDConnection.Create(Application);
    Connection.Params.Add('DriverID=MSAcc');
    Connection.Params.Add('Database=D:\donnees\TEST\GV\FireDacCheminLong\FireDacCheminLong\FireDacCheminLong\FireDacCheminLong\FireDacCheminLong\FireDacCheminLong\FireDacCheminLong\FireDacCheminLong\FireDacCheminLong\FireDacCheminLong\DC26.021248.PGOC.23.10.18_projCC45_dgn_topo.mdb');
    Connection.Name        := 'Test';
    Connection.Connected    := True;
    FDQuery := TFDQuery.Create(Application);
    FDQuery.Connection := Connection;
    FDQuery.SQL.Text := 'SELECT * FROM PointTopo';
    FDQuery.Active:= True;

finally
    FDQuery.Active:= False;
    Connection.Connected := False;
    FreeAndNil(Connection);
    FreeAndNil(FDQuery);
end;

这是一个有效的例子。数据库路径小于128

try
    Connection := TFDConnection.Create(Application);
    Connection.Params.Add('DriverID=MSAcc');
    Connection.Params.Add('Database=D:\donnees\TEST\GV\FireDacCheminLong\FireDacCheminLong\FireDacCheminLong\FireDacCheminLong\DC26.021248.PGOC.23.10.18_projCC45_dgn_topo.mdb');
    Connection.Name        := 'Test';
    Connection.Connected    := True;
    FDQuery := TFDQuery.Create(Application);
    FDQuery.Connection := Connection;
    FDQuery.SQL.Text := 'SELECT * FROM PointTopo';
    FDQuery.Active:= True;
finally
    FDQuery.Active:= False;
    Connection.Connected := False;
    FreeAndNil(Connection);
    FreeAndNil(FDQuery);
end;

当数据库路径的长度大于128时，如何执行查询？
Cyril