delphi - 如何使用 FireDAC 设置 Firebird (InterBase) 的事务锁定超时？

Question

使用时，TFDConnection 似乎没有设置 LOCK TIMEOUT

TFDConnection.UpdateOptions.LockMode := lmPessimistic;
TFDConnection.UpdateOptions.LockWait := true;

TFDTransaction 似乎也没有其属性。

The Firebird SET TRANSACTION documentation建议您可以设置LOCK TIMEOUT。

在设置超时属性时我是否忽略了某些内容，或者我是否必须在打开连接后执行SET TRANSACTION LOCK TIMEOUT？
如果我深入研究 FireDAC.Phys.IB*.pas 文件，我会看到对 isc_tpb_lock_timeout 的引用，但无法使用它们？

Answer 1

这可以通过 IBAdvanced 参数定义(请参阅 Connect to Interbase (FireDAC) ):

The ';' separated list of additional parameters. You can find the full list of the supported parameters in the FireDAC.Phys.IBWrapper unit (see the DPBInfos constant array). You can find the description of each Code listed there in the Interbase manuals.

这是 FireDAC.Phys.IBWrapper 中定义它们的部分^*:

const
  TRPBInfo_Items = 24;
  TRPBInfos: array[1 .. TRPBInfo_Items] of TIBPBInfo = (
    (Name: 'consistency';      ParamType: prNoneNoZ; Code: isc_tpb_consistency),
    (Name: 'concurrency';      ParamType: prNoneNoZ; Code: isc_tpb_concurrency),
    (Name: 'shared';           ParamType: prNoneNoZ; Code: isc_tpb_shared),
    (Name: 'protected';        ParamType: prNoneNoZ; Code: isc_tpb_protected),
    (Name: 'exclusive';        ParamType: prNoneNoZ; Code: isc_tpb_exclusive),
    (Name: 'wait';             ParamType: prNoneNoZ; Code: isc_tpb_wait),
    (Name: 'nowait';           ParamType: prNoneNoZ; Code: isc_tpb_nowait),
    (Name: 'read';             ParamType: prNoneNoZ; Code: isc_tpb_read),
    (Name: 'write';            ParamType: prNoneNoZ; Code: isc_tpb_write),
    (Name: 'lock_read';        ParamType: prStrg;    Code: isc_tpb_lock_read),
    (Name: 'lock_write';       ParamType: prStrg;    Code: isc_tpb_lock_write),
    (Name: 'verb_time';        ParamType: prNoneNoZ; Code: isc_tpb_verb_time),
    (Name: 'commit_time';      ParamType: prNoneNoZ; Code: isc_tpb_commit_time),
    (Name: 'ignore_limbo';     ParamType: prNoneNoZ; Code: isc_tpb_ignore_limbo),
    (Name: 'read_committed';   ParamType: prNoneNoZ; Code: isc_tpb_read_committed),
    (Name: 'autocommit';       ParamType: prNoneNoZ; Code: isc_tpb_autocommit),
    (Name: 'rec_version';      ParamType: prNoneNoZ; Code: isc_tpb_rec_version),
    (Name: 'no_rec_version';   ParamType: prNoneNoZ; Code: isc_tpb_no_rec_version),
    (Name: 'restart_requests'; ParamType: prNoneNoZ; Code: isc_tpb_restart_requests),
    (Name: 'no_auto_undo';     ParamType: prNoneNoZ; Code: isc_tpb_no_auto_undo),
    // IB75
    (Name: 'no_savepoint';     ParamType: prNoneNoZ; Code: isc_tpb_no_savepoint),
    // FB20
    (Name: 'lock_timeout';     ParamType: prCard;    Code: isc_tpb_lock_timeout),
    // IB2017
    (Name: 'exclusivity';      ParamType: prNoneNoZ; Code: isc_tpb_exclusive),
    (Name: 'wait_time';        ParamType: prCard;    Code: isc_tpb_wait_time)
   );

所以，例如5 秒超时:

TFDConnection.Params.Add('IBAdvanced=lock_timeout=5');

^{* 请注意，文档声明它们位于 DPBInfos 中，但它们位于 TRPBInfos 中。}